Mean sea level is an average level of the surface of one or more of Earth's oceans from which heights such as elevation may be measured. MSL is a type of vertical datum – a standardised geodetic datum –, used, for example, as a chart datum in cartography and marine navigation, or, in aviation, as the standard sea level at which atmospheric pressure is measured to calibrate altitude and aircraft flight levels. A common and straightforward mean sea-level standard is the midpoint between a mean low and mean high tide at a particular location. Sea levels can be affected by many factors and are known to have varied over geological time scales; however 20th century and current millennium sea level rise is caused by global warming, careful measurement of variations in MSL can offer insights into ongoing climate change. The term above sea level refers to above mean sea level. Precise determination of a "mean sea level" is difficult to achieve because of the many factors that affect sea level. Instantaneous sea level varies quite a lot on several scales of space.
This is because the sea is in constant motion, affected by the tides, atmospheric pressure, local gravitational differences, salinity and so forth. The easiest way this may be calculated is by selecting a location and calculating the mean sea level at that point and use it as a datum. For example, a period of 19 years of hourly level observations may be averaged and used to determine the mean sea level at some measurement point. Still-water level or still-water sea level is the level of the sea with motions such as wind waves averaged out. MSL implies the SWL further averaged over a period of time such that changes due to, e.g. the tides have zero mean. Global MSL refers to a spatial average over the entire ocean. One measures the values of MSL in respect to the land. In the UK, the Ordnance Datum is the mean sea level measured at Newlyn in Cornwall between 1915 and 1921. Prior to 1921, the vertical datum was MSL at the Victoria Liverpool. Since the times of the Russian Empire, in Russia and other former its parts, now independent states, the sea level is measured from the zero level of Kronstadt Sea-Gauge.
In Hong Kong, "mPD" is a surveying term meaning "metres above Principal Datum" and refers to height of 1.230m below the average sea level. In France, the Marégraphe in Marseilles measures continuously the sea level since 1883 and offers the longest collapsed data about the sea level, it is used for main part of Africa as official sea level. As for Spain, the reference to measure heights below or above sea level is placed in Alicante. Elsewhere in Europe vertical elevation references are made to the Amsterdam Peil elevation, which dates back to the 1690s. Satellite altimeters have been making precise measurements of sea level since the launch of TOPEX/Poseidon in 1992. A joint mission of NASA and CNES, TOPEX/Poseidon was followed by Jason-1 in 2001 and the Ocean Surface Topography Mission on the Jason-2 satellite in 2008. Height above mean sea level is the elevation or altitude of an object, relative to the average sea level datum, it is used in aviation, where some heights are recorded and reported with respect to mean sea level, in the atmospheric sciences, land surveying.
An alternative is to base height measurements on an ellipsoid of the entire Earth, what systems such as GPS do. In aviation, the ellipsoid known as World Geodetic System 84 is used to define heights; the alternative is to use a geoid-based vertical datum such as NAVD88. When referring to geographic features such as mountains on a topographic map, variations in elevation are shown by contour lines; the elevation of a mountain denotes the highest point or summit and is illustrated as a small circle on a topographic map with the AMSL height shown in metres, feet or both. In the rare case that a location is below sea level, the elevation AMSL is negative. For one such case, see Amsterdam Airport Schiphol. To extend this definition far from the sea means comparing the local height of the mean sea surface with a "level" reference surface, or geodetic datum, called the geoid. In a state of rest or absence of external forces, the mean sea level would coincide with this geoid surface, being an equipotential surface of the Earth's gravitational field.
In reality, due to currents, air pressure variations and salinity variations, etc. this does not occur, not as a long-term average. The location-dependent, but persistent in time, separation between mean sea level and the geoid is referred to as ocean surface topography, it varies globally in a range of ± 2 m. Adjustments were made to sea-level measurements to take into account the effects of the 235 lunar month Metonic cycle and the 223-month eclipse cycle on the tides. Several terms are used to describe the changing relationships between sea level and dry land; when the term "relative" is used, it means change relative to a fixed point in the sediment pile. The term "eustatic" refers to global changes in sea level relative to a fixed point, such as the centre of the earth, for example as a result of melting ice-caps; the term "steric" refers to global changes in sea level due to thermal expansion and salinity variations. The term "isostatic" refers to changes in
Battle of Gettysburg, First Day
The First Day of the Battle of Gettysburg during the American Civil War took place on July 1, 1863, began as an engagement between isolated units of the Army of Northern Virginia under Confederate General Robert E. Lee and the Army of the Potomac under Union Maj. Gen. George G. Meade, it soon escalated into a major battle which culminated in the outnumbered and defeated Union forces retreating to the high ground south of Gettysburg, Pennsylvania. The first-day battle proceeded in three phases. In the morning, two brigades of Confederate Maj. Gen. Henry Heth's division were delayed by dismounted Union cavalrymen under Brig. Gen. John Buford; as infantry reinforcements arrived under Maj. Gen. John F. Reynolds of the Union I Corps, the Confederate assaults down the Chambersburg Pike were repulsed, although Gen. Reynolds was killed. By early afternoon, the Union XI Corps, commanded by Major General Oliver Otis Howard, had arrived, the Union position was in a semicircle from west to north of the town.
The Confederate Second Corps under Lt. Gen. Richard S. Ewell began a massive assault from the north, with Maj. Gen. Robert E. Rodes's division attacking from Oak Hill and Maj. Gen. Jubal A. Early's division attacking across the open fields north of town; the Union lines held under heavy pressure, although the salient at Barlow's Knoll was overrun. The third phase of the battle came as Rodes renewed his assault from the north and Heth returned with his entire division from the west, accompanied by the division of Maj. Gen. W. Dorsey Pender. Heavy fighting in Herbst's Woods and on Oak Ridge caused the Union line to collapse; some of the Federals conducted a fighting withdrawal through the town, suffering heavy casualties and losing many prisoners. They waited for additional attacks. Despite discretionary orders from Robert E. Lee to take the heights "if practicable," Richard Ewell chose not to attack. Historians have debated since how the battle might have ended differently if he had found it practicable to do so.
On the morning of July 1, Union cavalry in the division of Brigadier General John Buford were awaiting the approach of Confederate infantry forces from the direction of Cashtown, to the northwest. Confederate forces from the brigade of Brig. Gen. J. Johnston Pettigrew had clashed with Union forces the day before but believed they were Pennsylvania militia of little consequence, not the regular army cavalry, screening the approach of the Army of the Potomac. General Buford recognized the importance of the high ground directly to the south of Gettysburg, he knew that if the Confederates could gain control of the heights, Meade's army would have a hard time dislodging them. He decided to utilize three ridges west of Gettysburg: Herr Ridge, McPherson Ridge, Seminary Ridge; these were appropriate terrain for a delaying action by his small division against superior Confederate infantry forces, meant to buy time awaiting the arrival of Union infantrymen who could occupy the strong defensive positions south of town, Cemetery Hill, Cemetery Ridge, Culp's Hill.
Early that morning, commanding the Left Wing of the Army of the Potomac, ordered his corps to march to Buford's location, with the XI Corps to follow behind. Confederate Maj. Gen. Henry Heth's division, from Lt. Gen. A. P. Hill's Third Corps, advanced towards Gettysburg. Heth deployed no cavalry and led, with the artillery battalion of Major William J. Pegram. Two infantry brigades followed, commanded by Brig. Gens. James J. Archer and Joseph R. Davis, proceeding easterly in columns along the Chambersburg Pike. Three miles west of town, about 7:30 a.m. Heth's two brigades met light resistance from cavalry vedettes and deployed into line, they reached dismounted troopers from Col. William Gamble's cavalry brigade; the first shot of the battle was claimed to be fired by Lieutenant Marcellus E. Jones of the 8th Illinois Cavalry, fired at an unidentified man on a gray horse over a half-mile away. Buford's 2,748 troopers would soon be faced with 7,600 Confederate infantrymen, deploying from columns into line of battle.
Gamble's men mounted determined resistance and delaying tactics from behind fence posts with rapid fire from their breech-loading carbines. It is a modern myth, they were able to fire two or three times faster than a muzzle-loaded carbine or rifle. The breech-loading design meant that Union troops did not have to stand to reload and could do so safely behind cover; this was a great advantage over the Confederates, who still had to stand to reload, thus providing an easier target. But this was so far a bloodless affair. By 10:20 a.m. the Confederates had reached Herr Ridge and had pushed the Federal cavalrymen east to McPherson Ridge, when the vanguard of the I Corps arrived, the division of Maj. Gen. James S. Wadsworth; the troops were led by Gen. Reynolds, who conferred with Buford and hurried back to bring more men forward; the morning infantry fighting occurred on either side of the Chambersburg Pike on McPherson Ridge. To the north, an unfinished railroad bed opened three shallow cuts in the ridges.
To the south, the dominant features were Herbst Woods. Brig. Gen. Lysander Cutler's Union brigade opposed Davis's brigade.
I Corps (Union Army)
I Corps was the designation of three different corps-sized units in the Union Army during the American Civil War. Separate formation called the I Corps served in the Army of the Ohio/Army of the Cumberland under Alexander M. McCook from September 29, 1862 to November 5, 1862, in the Army of the Mississippi under George W. Morgan from January 4, 1863 to January 12, 1863, in the Army of the Potomac and Army of Virginia; the first two were units of limited life. The term "First Corps" is used to describe the First Veteran Corps from 1864 to 1866; the I Corps was created on March 3, 1862, when President Abraham Lincoln ordered the creation of a five-corps army under the command of Major General George B. McClellan; the first commander of the corps was Major General Irvin McDowell. It contained three divisions under the commands of Brigadier Generals William B. Franklin, George A. McCall, Rufus King. McClellan intended for the I Corps to participate in his Peninsula Campaign with the rest of the army, but after Stonewall Jackson initiated his Valley Campaign on March 23 at the First Battle of Kernstown, President Lincoln decided to keep the corps in northern Virginia to protect Washington.
On April 4, Lincoln created the Department of the Rappahannock, detaching the I Corps from the Army of the Potomac to form the core of the new department, giving command of the department to I Corps commander, Irvin McDowell. In May, Franklin’s division was detached and sent south to reinforce McClellan in his Peninsula campaign, uniting with a division of the IV Corps to form the VI Corps. On June 18, McCall’s division, the “Pennsylvania Reserves”, was detached and sent to join McClellan’s army on the Virginia Peninsula. Temporarily attached to the V Corps, it saw heavy action at Glendale. Division commander Brig. Gen. George McCall and future I Corps commander Brig. Gen. John Reynolds were both captured and freed in a prisoner exchange that August. On June 26, Rufus King’s division, James B. Ricketts’ division, Abner Doubleday’s brigade were transferred from the Department of the Rappahannock to the newly created Army of Virginia, forming its III Corps, under the command of Irvin McDowell.
On August 26, the “Pennsylvania Reserves” were transferred to the III Corps of the Army of Virginia and fought at the Second Battle of Bull Run. Soon after the battle, the corps was transferred to the Army of the Potomac and reclassified as the I Corps of the Army of the Potomac. In early September, the I Corps, now under the command of Major General Joseph Hooker, followed Lee through Maryland and fought at South Mountain and Antietam. John Reynolds was temporarily detached to train militia troops in his home state of Pennsylvania and did not participate in the Maryland Campaign. At Antietam, the I Corps was the first corps engaged, suffered enormous losses in the fighting around the cornfield and Dunker Church. Hooker was wounded in the foot during the command of the I Corps devolved on Meade. In October, Reynolds was made commander of the corps. Having fought three battles in six weeks, the I Corps was depleted. An influx of new volunteer regiments arrived to replenish its ranks, by November it was back up to full strength.
The corps moved southward to fight General Robert E. Lee's army at the Battle of Fredericksburg, commanded by Major General John F. Reynolds, arguably the best Union corps commander in the Eastern Theater. At Fredericksburg and John Gibbon's divisions fought Stonewall Jackson's corps south of the town while Doubleday's division was held in reserve; the I Corps did not see any significant action in the Chancellorsville Campaign. In its last major battle, the Battle of Gettysburg, General Reynolds was killed just as the first troops arrived on the field, command was inherited by Major General Abner Doubleday. Although putting up a ferocious fight, the I Corps was overwhelmed by the Confederate Third Corps and Robert E. Rodes's division of Richard S. Ewell's Second Corps, it was forced to retreat through the town of Gettysburg, taking up defensive positions on Cemetery Hill after the 16th Maine's brave stand of which only 39 soldiers returned. The next day, the command was given to Major General John Newton, a division commander from the VI Corps.
This was a controversial move that offended the more senior Doubleday. Newton led it through the remainder of the battle, including the defense against Pickett's Charge, through the Mine Run Campaign that fall. On March 24, 1864, the Civil War career of the I Corps came to an end as it was disbanded and its depleted units were reorganized into two divisions, which were transferred into the V Corps of the Army of the Potomac. * As III Corps, Army of Virginia I Corps Eicher, John H. & Eicher, David J.: Civil War High Commands, Stanford University Press, 2001, ISBN 0-8047-3641-3 Fox, William F.: Regimental Losses in the American Civil War, Albany Publishing, 1889
Army of the Potomac
The Army of the Potomac was the principal Union Army in the Eastern Theater of the American Civil War. It was created in July 1861 shortly after the First Battle of Bull Run and was disbanded in May 1865 following the surrender of the Confederate Army of Northern Virginia in April; the Army of the Potomac was created in 1861 but was only the size of a corps. Its nucleus was called the Army of Northeastern Virginia, under Brig. Gen. Irvin McDowell, it was the army that fought the war's first major battle, the First Battle of Bull Run; the arrival in Washington, D. C. of Maj. Gen. George B. McClellan changed the makeup of that army. McClellan's original assignment was to command the Division of the Potomac, which included the Department of Northeast Virginia under McDowell and the Department of Washington under Brig. Gen. Joseph K. Mansfield. On July 26, 1861, the Department of the Shenandoah, commanded by Maj. Gen. Nathaniel P. Banks, was merged with McClellan's departments and on that day, McClellan formed the Army of the Potomac, composed of all military forces in the former Departments of Northeastern Virginia, Washington and the Shenandoah.
The men under Banks's command became an infantry division in the Army of the Potomac. The army started with four corps, but these were divided during the Peninsula Campaign to produce two more. After the Second Battle of Bull Run, the Army of the Potomac absorbed the units that had served under Maj. Gen. John Pope, it is a popular, but mistaken, belief that John Pope commanded the Army of the Potomac in the summer of 1862 after McClellan's unsuccessful Peninsula Campaign. On the contrary, Pope's army consisted of different units, was named the Army of Virginia. During the time that the Army of Virginia existed, the Army of the Potomac was headquartered on the Virginia Peninsula, outside Washington, D. C. with McClellan still in command, although three corps of the Army of the Potomac were sent to northern Virginia and were under Pope's operational control during the Northern Virginia Campaign. The Army of the Potomac underwent many structural changes during its existence; the army was divided by Ambrose Burnside into three grand divisions of two corps each with a Reserve composed of two more.
Hooker abolished the grand divisions. Thereafter the individual corps, seven of which remained in Virginia, reported directly to army headquarters. Hooker created a Cavalry Corps by combining units that had served as smaller formations. In late 1863, two corps were sent West, and— in 1864— the remaining five corps were recombined into three. Burnside's IX Corps, which accompanied the army at the start of Ulysses S. Grant's Overland Campaign, rejoined the army later. For more detail, see the section Corps below; the Army of the Potomac fought in most of the Eastern Theater campaigns in Virginia and Pennsylvania. After the end of the war, it was disbanded on June 28, 1865, shortly following its participation in the Grand Review of the Armies; the Army of the Potomac was the name given to General P. G. T. Beauregard's Confederate army during the early stages of the war. However, the name was changed to the Army of Northern Virginia, which became famous under General Robert E. Lee. In 1869 the Society of the Army of the Potomac was formed as a veterans association.
It had its last reunion in 1929. Because of its proximity to the large cities of the North, such as Washington, D. C. Philadelphia, New York City, the Army of the Potomac received more contemporary media coverage than the other Union field armies; such coverage produced fame for a number of this army's units. Individual brigades, such as the Irish Brigade, the Philadelphia Brigade, the First New Jersey Brigade, the Vermont Brigade, the Iron Brigade, all became well known to the general public, both during the Civil War and afterward; the army consisted of fourteen divisions commanded by Edwin Sumner, William B. Franklin, Louis Blenker, Nathaniel Banks, Frederick W. Lander, Silas Casey, Irvin McDowell, Fitz-John Porter, Samuel Heintzelman, Erasmus Keyes, William F. Smith, Charles P. Stone, George McCall; because this arrangement would be too hard to control in battle, President Lincoln issued an order on March 13, 1862, dividing the army into six corps headed by Sumner, Banks, McDowell and Keyes, the highest-ranking officers.
McClellan was not happy with this, as he had intended to wait until the army had been tested in battle before judging which generals were suitable for corps command. After the Battle of Williamsburg on May 5, McClellan requested and obtained permission to create two additions corps. Gen Fitz-John Porter, the VI Corps, headed by Brig. Gen William B. Franklin, both personal favorites of his. After the Battle of Kernstown in the Valley on March 23, the administration became paranoid about "Stonewall" Jackson's activities there and the potential danger they posed to Washington D. C. and to McClellan's displeasure, detached Blenker's division from the II Corps and sent it to West Virginia to serve under John C. Fremont's command. McDowell's corps was stationed in the Rappahannock area. In June 1862, George McCall's division from McDowell's corps was sent down to the Peninsula and temporarily attached to the V Corps. In the Seven Days Battles, the V Corps was engaged; the Pennsylvania Reserves, in particular, suffered heavy loss
Richard S. Ewell
Richard Stoddert Ewell was a career United States Army officer and a Confederate general during the American Civil War. He achieved fame as a senior commander under Stonewall Jackson and Robert E. Lee and fought through much of the war, but his legacy has been clouded by controversies over his actions at the Battle of Gettysburg and at the Battle of Spotsylvania Court House. Ewell was born in District of Columbia, he was raised in Prince William County, from the age of 3, at an estate near Manassas known as "Stony Lonesome." He was the third son of Elizabeth Stoddert Ewell. S. Secretary of the Navy, he graduated from the United States Military Academy in 1840. He was known to his friends as "Old Bald Head" or "Baldy." He was commissioned a second lieutenant in the 1st U. S. Dragoons and was promoted to first lieutenant in 1845. From 1843 to 1845 he served with Philip St. George Cooke and Stephen Watts Kearny on escort duty along the Santa Fe and Oregon Trails. In the Mexican–American War, serving under Winfield Scott, he was recognized and promoted to captain for his courage at Contreras and Churubusco.
At Contreras, he conducted a nighttime reconnaissance with engineer Captain Robert E. Lee, his future commander. Ewell served in the New Mexico Territory for some time, exploring the newly acquired Gadsden Purchase with Colonel Benjamin Bonneville, he was wounded in a skirmish with Apaches under Cochise in 1859. In 1860, while in command of Fort Buchanan, illness compelled him to leave the West for Virginia to recuperate, he described his condition as "very ill with vertigo, etc. and now am excessively debilitated having occasional attacks of the ague." Illnesses and injuries would cause difficulties for him throughout the upcoming Civil War. As the nation moved towards Civil War, Ewell had pro-Union sentiments, but when his home state of Virginia seceded, Ewell resigned his U. S. Army commission on May 1861, to join the Virginia Provisional Army, he was appointed a colonel of cavalry on May 9 and was the first officer of field grade wounded in the war, at a May 31 skirmish at Fairfax Court House where he was hit in the shoulder.
He was promoted to brigadier general in the Confederate States Army on June 17 and commanded a brigade in the Army of the Potomac at the First Battle of Bull Run, but saw little action. Hours after the battle, Ewell proposed to President Jefferson Davis that in order for the Confederacy to win the war, the slaves must be freed and join the ranks of the army, but Davis considered that "impossible" and that topic never came up between Ewell again. Ewell, like Patrick Cleburne, was one of those few Confederate generals who saw that the Confederacy needed all the manpower it could get, regardless of race. In late July, Ewell was furious when he heard that his commanding officer, P. G. T. Beauregard, was blaming him for not following orders at Bull Run, when in fact, the orders never reached him in time. Ewell inspired his men in spite of, not because of, his appearance. Historian Larry Tagg described him: Rather short at 5 feet 8 inches, he had just a fringe of brown hair on an otherwise bald, bomb-shaped head.
Bright, bulging eyes protruded above a prominent nose, creating an effect which many likened to a bird—an eagle, some said, or a woodcock—especially when he let his head droop toward one shoulder, as he did, uttered strange speeches in his shrill, twittering lisp. He had a habit of muttering odd remarks in the middle of normal conversation, such as "Now why do you suppose President Davis made me a major general anyway?" He could be blisteringly profane. He was so nervous and fidgety he could not sleep in a normal position, spent nights curled around a camp stool, he had convinced himself that he had some mysterious internal "disease," and so subsisted entirely on frumenty, a dish of hulled wheat boiled in milk and sweetened with sugar. A "compound of anomalies" was, he was the reigning eccentric of the Army of Northern Virginia, his men, who knew at first hand his bravery and generosity of spirit, loved him all the more for it. On January 24, 1862, Ewell was promoted to major general, his division was left around Culpeper when General Johnston moved his army to the Virginia Peninsula.
Ewell moved west, crossing the Blue Ridge, began serving under Thomas J. "Stonewall" Jackson during the Valley Campaign. Although the two generals worked together well, both were noted for their quixotic personal behavior, there were many stylistic differences between them. Jackson was stern and pious, whereas Ewell was witty and profane. Jackson was flexible and intuitive on the battlefield, while Ewell, although brave and effective, required precise instructions to function effectively. Ewell was resentful about Jackson's tendency to keep his subordinates uninformed about his tactical plans, but Ewell adjusted to Jackson's methods. Ewell superbly commanded a division in Jackson's small army during the Valley Campaign winning quite a few battles against the larger Union armies of Maj. Gens. Nathaniel P. Banks, John C. Frémont, James Shields at the Battle of Front Royal and First Battle of Winchester, Battle of Cross Keys, Battle of Port Republic, respectively. Jackson's army was recalled to Richmond to join Robert E. Lee in protecting the city against Maj. Gen. George B. McClellan's Army of the Potomac in the Peninsula Campaign.
Ewell fought conspicuously at Gaines' M
Battle of Gettysburg, Second Day
During the second day of the Battle of Gettysburg Confederate Gen. Robert E. Lee attempted to capitalize on his first day's success, he launched the Army of Northern Virginia in multiple attacks on the flanks of the Union Army of the Potomac, commanded by Maj. Gen. George G. Meade; the assaults were unsuccessful, resulted in heavy casualties for both sides. After a short delay to assemble his forces and avoid detection in his approach march, Lt. Gen. James Longstreet attacked with his First Corps against the Union left flank, his division under Maj. Gen. John Bell Hood attacked Devil's Den. To Hood's left, Maj. Gen. Lafayette McLaws attacked the Peach Orchard. Although neither prevailed, the Union III Corps was destroyed as a combat organization as it attempted to defend a salient over too wide a front. Gen. Meade rushed as many as 20,000 reinforcements from elsewhere in his line to resist these fierce assaults; the attacks in this sector concluded with an unsuccessful assault by the Third Corps division of Maj. Gen. Richard H. Anderson against the Union center on Cemetery Ridge.
That evening, Confederate Second Corps commander Lt. Gen. Richard S. Ewell turned demonstrations against the Union right flank into full-scale assaults on Culp's Hill and East Cemetery Hill, but both were repulsed; the Union army had occupied strong defensive positions, Meade handled his forces well, resulting in heavy losses for both sides but leaving the disposition of forces on both sides unchanged. Lee's hope of crushing the Army of the Potomac on Northern territory was dashed, but undaunted, he began to plan for the third day of fighting; this article includes details of many attacks on the Union left flank and center, but separate articles describe other major engagements in this massive battle of the second day: Little Round Top Culp's Hill Cemetery Hill By the morning of July 2, six of the seven corps of the Army of the Potomac had arrived on the battlefield. The I Corps and the XI Corps had fought hard on the first day, they were joined that evening by the yet-unengaged troops of the XII Corps, III Corps, II Corps, on the morning of July 2 by the V Corps.
The VI Corps was still 30 miles away in Maryland, on that morning. They assumed positions in a fish hook shape about three miles long, from Culp's Hill, around to Cemetery Hill, down the spine of Cemetery Ridge; the Army of Northern Virginia line was parallel to the Union's, on Seminary Ridge and on an arc northwest and northeast of the town of Gettysburg. All of the Second Corps and Third Corps were present, the First Corps was arriving from Cashtown. Robert E. Lee had several choices to consider for his next move, his order of the previous evening that Ewell occupy Culp's Hill or Cemetery Hill "if practicable" was not realized, the Union army was now in strong defensive positions with compact interior lines. His senior subordinate, counseled a strategic move—the Army should leave its current position, swing around the Union left flank, interpose itself on Meade's lines of communication, inviting an attack by Meade that could be received on advantageous ground. Longstreet argued that this was the entire point of the Gettysburg campaign, to move strategically into enemy territory but fight only defensive battles there.
Lee rejected this argument because he was concerned about the morale of his soldiers having to give up the ground for which they fought so hard the day before. He wanted to retain the initiative and had a high degree of confidence in the ability of his army to succeed in any endeavor, an opinion bolstered by their spectacular victories the previous day and at Chancellorsville, he was therefore determined to attack on July 2. Lee wanted to seize the high ground south of Gettysburg Cemetery Hill, which dominated the town, the Union supply lines, the road to Washington, D. C. and he believed. He desired an early-morning assault by Longstreet's Corps, reinforced by Ewell, who would move his Corps from its current location north of town to join Longstreet. Ewell protested this arrangement, claiming his men would be demoralized if forced to move from the ground they had captured, and Longstreet protested. Lee compromised with his subordinates. Ewell would remain in place and conduct a demonstration against Culp's Hill, pinning down the right flank of the Union defenders so that they could not reinforce their left, where Longstreet would launch the primary attack as soon as he was ready.
Ewell's demonstration would be turned into a full-scale assault. Lee ordered Longstreet to launch a surprise attack with two divisions straddling, guiding on, the Emmitsburg Road. Hood's division would move up the eastern side of the road, Lafayette McLaws's the western side, each perpendicular to it; the objective was to strike the Union Army in an oblique attack, rolling up their left flank, collapsing the line of Union corps onto each other, seizing Cemetery Hill. The Third Corps division of Richard H. Anderson would join the attack against the center of the Union li
Devils Den is a boulder-strewn hill on the south end of Houck's Ridge at Gettysburg Battlefield, once used by artillery and infantry on the second day of the 1863 Battle of Gettysburg during the American Civil War. A tourist attraction since the memorial association era, several boulders are worn from foot traffic and the site includes numerous cannon and walkways, including a bridge spanning two boulders. Devils Den was formed with Little Round Top and Big Round Top by periglacial frost wedging of the igneous landform formed 200 million years ago when a diabase sill intruded through the Triassic Gettysburg plain; the feature acquired its foreboding name prior to the 1863 battle. Throughout the mid-19th Century, local residents believed that the crevices between the boulders were home to a large snake; the size of the reptile varied between accounts, but reports ranged from 8 ft to as large as 15 ft. The snake became known as "The Devil," and thus the area he was believed to inhabit became known as "The Devil’s Den."
Some soldiers' accounts used the name "Devil's Cave", a depression on a boulder that collects water resembles a flying horned bat. On July 2, 1863, Smith's Union battery, with six Napoleon smooth-bores, used the hill to counterfire on Confederate artillery prior to McLaws' Assault at 5:30 pm. Against Hood's Assault that started at 4 pm, Devils Den was defended by Birney's 1st Division as the far left position from The Peach Orchard Salient of the III Corps; the hill was captured when the "First Texas Regiment, having pressed forward to the crest of the hill and driven the enemy from his battery", Anderson's Confederates used the hill for the first attack on The Wheatfield. From near the Slaughter Pen, the 40th New York Volunteer Infantry Regiment forced the 2nd & 17th Georgia regiments of Benning's Brigade to retreat to Devils Den. Confederate sharpshooters were stationed between the rocks to fire upon Union soldiers at Little Round Top, among their victims being General Stephen H. Weed and Lieutenant Charles E. Hazlett.
Hazlett's guns counter-fired upon them, many were killed from the concussion of air. The 124th NY monument with Ellis statue was dedicated near Devil's Den in 1884. Postbellum avenues were constructed to Devil's Den such as Sickles' Avenue from the west, Crawford Avenue in 1895, Warren Avenue across Plum Run. From 1894-1916, the Gettysburg Electric Railway operated on a curve crossing Plum Run around the south base of the hill with the Tipton Station providing Devil's Den services. In 1916, a Devil's Den boulder was used as a Satterlee Hospital memorial at Philadelphia's Clark Park; the nearby 1933 comfort station was demolished in 2009, its access bridge over Plum Run remains to the east. In 1952, ROTC students conducted a mock battle at the site, the "Devil's Den Access Committee" was formed in 1988; the site's ID Tablet was designated a Historic District Contributing Structure in 2004, the Devil's Den barricade is structure WA35 on the Gettysburg National Military Park's List of Classified Structures.
History. Net:Devil's Den