USS Pivot (AM-276)
USS Pivot, an Admirable-class minesweeper, was the first ship of the United States Navy named Pivot. She was built at the Gulf Shipbuilding Corporation, Alabama. Mrs. Clara L. Prouty christened Pivot on 11 November 1943, her trials started 12 July 1944 in the Gulf of Mexico and initial training was in the Chesapeake Bay. After shakedown ended 10 September, the new minesweeper operated with the Atlantic Fleet training and patrolling until sailing for the Pacific early in April 1945, she transited the Panama Canal on 10 April 1945. She supported Admiral Marc Mitscher's Fast Carrier Task Force during the deadly strikes against Japan in July and operated in Korean waters after Japan's surrender, she resumed sweeping operations in the Ryukyus. She received four battle stars for World War II. Pivot was decommissioned 6 November 1946 at Subic Bay, Philippines, she was renamed ROCS Yung Shou. On 1 July 1970, Yung Shou was decommissioned; this article incorporates text from the public domain Dictionary of American Naval Fighting Ships.
The entry can be found here. Photo gallery of Pivot at NavSource Naval History
The Russo-Japanese War was fought during 1904-1905 between the Russian Empire and the Empire of Japan over rival imperial ambitions in Manchuria and Korea. The major theatres of operations were the Liaodong Peninsula and Mukden in Southern Manchuria and the seas around Korea and the Yellow Sea. Russia sought a warm-water port on the Pacific Ocean for maritime trade. Vladivostok was operational only during the summer, whereas Port Arthur, a naval base in Liaodong Province leased to Russia by China, was operational all year. Since the end of the First Sino-Japanese War in 1895, Japan feared Russian encroachment on its plans to create a sphere of influence in Korea and Manchuria. Russia had demonstrated an expansionist policy in the Siberian Far East from the reign of Ivan the Terrible in the 16th century. Seeing Russia as a rival, Japan offered to recognize Russian dominance in Manchuria in exchange for recognition of Korea as being within the Japanese sphere of influence. Russia refused and demanded Korea north of the 39th parallel to be a neutral buffer zone between Russia and Japan.
The Japanese government perceived a Russian threat to its plans for expansion into Asia and chose to go to war. After negotiations broke down in 1904, the Japanese Navy opened hostilities by attacking the Russian Eastern Fleet at Port Arthur, China, in a surprise attack. Russia suffered multiple defeats by Japan, but Tsar Nicholas II was convinced that Russia would win and chose to remain engaged in the war. Russia ignored Japan's willingness early on to agree to an armistice and rejected the idea to bring the dispute to the Arbitration Court at The Hague; the war concluded with the Treaty of Portsmouth, mediated by US President Theodore Roosevelt. The complete victory of the Japanese military surprised world observers; the consequences transformed the balance of power in East Asia, resulting in a reassessment of Japan's recent entry onto the world stage. It was the first major military victory in the modern era of an Asian power over a European one. Scholars continue to debate the historical significance of the war.
After the Meiji Restoration in 1868, the Meiji government endeavored to assimilate Western ideas, technological advances and ways of warfare. By the late 19th century, Japan had transformed itself into a modernized industrial state; the Japanese wanted to be recognized as equal with the Western powers. The Meiji Restoration had been intended to make Japan a modernized state, not a Westernized one, Japan was an imperialist power, looking towards overseas expansionism. In the years 1869–73, the Seikanron had bitterly divided the Japanese elite between one faction that wanted to conquer Korea vs. another that wanted to wait until Japan was more modernized before embarking on a war to conquer Korea. Worse, the Western Powers were conquering small pieces of China and China had dominated Korea with its military for centuries; the Japanese were doing what they could to emulate the West in every way possible, including conqering and occupying its neighbors. In much the same way that Europeans used the "backwardness" of African and Asian nations as a reason for why they had to conquer them, for the Japanese elite the "backwardness" of China and Korea was proof of the inferiority of those nations, thus giving the Japanese the "right" to conquer them.
Inouye Kaoru, the Foreign Minister, gave a speech in 1887 saying "What we must do is to transform our empire and our people, make the empire like the countries of Europe and our people like the peoples of Europe", going to say that the Chinese and Koreans had forfeited their right to be independent by not modernizing. Much of the pressure for an aggressive foreign policy in Japan came from below, with the advocates of "people's rights" movement calling for an elected parliament favoring an ultra-nationalist line that took it for granted the Japanese had the "right" to annex Korea, as the "people's right" movement was led by those who favored invading Korea in the years 1869–73; as part of the modernization process in Japan, Social Darwinian ideas about the "survival of the fittest" were common in Japan from the 1880s onward and many ordinary Japanese resented the heavy taxes imposed by the government to modernize Japan, demanding something tangible like an overseas colony as a reward for their sacrifices.
Furthermore, the educational system of Meiji Japan was meant to train the schoolboys to be soldiers when they grew up, as such, Japanese schools indoctrinated their students into Bushidō, the fierce code of the samurai. Having indoctrinated the younger generations into Bushidō, the Meiji elite found themselves faced with a people who clamored for war, regarded diplomacy as a weakness; the British Japanologist Richard Storry wrote the biggest misconception about Japan in the West was that the Japanese people were the "docile" instruments of the elite, when in fact much of the pressure for Japan's wars from 1894 to 1941 came from below, as ordinary people demanded a "tough" foreign policy, tended to engage in riots and assassination when foreign policy was perceived to be pusillanimous. Though the Meiji oligarchy refused to allow democracy, they did seek to appropriate some of the demands of the "people's rights" movement by allowing an elected Diet in 1890 (with limited powers and an equally
Degaussing is the process of decreasing or eliminating a remnant magnetic field. It is named after the gauss, a unit of magnetism, which in turn was named after Carl Friedrich Gauss. Due to magnetic hysteresis, it is not possible to reduce a magnetic field to zero, so degaussing induces a small "known" field referred to as bias. Degaussing was applied to reduce ships' magnetic signatures during World War II. Degaussing is used to reduce magnetic fields in cathode ray tube monitors and to destroy data held on magnetic storage; the term was first used by then-Commander Charles F. Goodeve, RCNVR, during World War II while trying to counter the German magnetic naval mines that were playing havoc with the British fleet; the mines detected the increase in the magnetic field when the steel in a ship concentrated the Earth's magnetic field over it. Admiralty scientists, including Goodeve, developed a number of systems to induce a small "N-pole up" field into the ship to offset this effect, meaning that the net field was the same as the background.
Since the Germans used the gauss as the unit of the strength of the magnetic field in their mines' triggers, Goodeve referred to the various processes to counter the mines as "degaussing". The term became a common word; the original method of degaussing was to install electromagnetic coils into the ships, known as coiling. In addition to being able to bias the ship continually, coiling allowed the bias field to be reversed in the southern hemisphere, where the mines were set to detect "S-pole down" fields. British ships, notably cruisers and battleships, were well protected by about 1943. Installing such special equipment was, far too expensive and difficult to service all ships that would need it, so the navy developed an alternative called wiping, which Goodeve devised, and, now called deperming; this procedure dragged a large electrical cable along the side of the ship with a pulse of about 2000 amperes flowing through it. This induced the proper field into the ship in the form of a slight bias.
It was thought that the pounding of the sea and the ship's engines would randomize this field, but in testing, this was found not to be a real problem. A more serious problem was realized: as a ship travels through Earth's magnetic field, it will pick up that field, counteracting the effects of the degaussing. From on captains were instructed to change direction as as possible to avoid this problem; the bias did wear off and ships had to be degaussed on a schedule. Smaller ships continued to use wiping through the war. To aid the Dunkirk evacuation, the British "wiped" 400 ships in four days. During World War II, the United States Navy commissioned a specialized class of degaussing ships that were capable of performing this function. One of them, USS Deperm, was named after the procedure. After the war, the capabilities of the magnetic fuzes were improved, by detecting not the field itself, but changes in it; this meant a degaussed ship with a magnetic "hot spot". Additionally, the precise orientation of the field was measured, something a simple bias field could not remove, at least for all points on the ship.
A series of ever-increasingly complex coils were introduced to offset these effects, with modern systems including no fewer than three separate sets of coils to reduce the field in all axes. The US Navy tested, in April 2009, a prototype of its High-Temperature Superconducting Degaussing Coil System, referred to as "HTS Degaussing"; the system works by encircling the vessel with superconducting ceramic cables whose purpose is to neutralize the ship's magnetic signature, as in the legacy copper systems. The main advantage of the HTS Degaussing Coil system is reduced weight and increased efficiency. A sea-going metal-hulled ship or submarine, by its nature, develops a magnetic signature as it travels, due to a magneto-mechanical interaction with Earth's magnetic field, it picks up the magnetic orientation of the earth's magnetic field where it is built. This signature can be exploited by magnetic mines or facilitate the detection of a submarine by ships or aircraft with magnetic anomaly detection equipment.
Navies use the deperming procedure, in conjunction with degaussing, as a countermeasure against this. Specialized deperming facilities, such as the United States Navy's Lambert's Point Deperming Station at Naval Station Norfolk, or Pacific Fleet Submarine Drive-In Magnetic Silencing Facility at Joint Base Pearl Harbor–Hickam, are used to perform the procedure. During a closed-wrap magnetic treatment, heavy-gauge copper cables encircle the hull and superstructure of the vessel, high electrical currents are pulsed through the cables; this has the effect of "resetting" the ship's magnetic signature to the ambient level after flashing its hull with electricity. It is possible to assign a specific signature, best suited to the particular area of the world in which the ship will operate. In drive-in magnetic silencing facilities, all cables are either hung above, below and on the sides, or concealed within the structural elements of facilities. Deperming is "permanent", it is only done once unless structural modifications are done to the ship.
With the introduction of iron ships, the negative effect of the metal hull on steering compasses was noted. It was observed that lightning strikes had a significant effect on compass deviation, identified in some extreme cases as being caused by the reversal of the ship's magnetic signature. In 1866, Evan Hopkins of London registered a patent for a pro
The Ming dynasty was the ruling dynasty of China – known as the Great Ming Empire – for 276 years following the collapse of the Mongol-led Yuan dynasty. The Ming dynasty was the last imperial dynasty in China ruled by ethnic Han Chinese. Although the primary capital of Beijing fell in 1644 to a rebellion led by Li Zicheng, regimes loyal to the Ming throne – collectively called the Southern Ming – survived until 1683; the Hongwu Emperor attempted to create a society of self-sufficient rural communities ordered in a rigid, immobile system that would guarantee and support a permanent class of soldiers for his dynasty: the empire's standing army exceeded one million troops and the navy's dockyards in Nanjing were the largest in the world. He took great care breaking the power of the court eunuchs and unrelated magnates, enfeoffing his many sons throughout China and attempting to guide these princes through the Huang-Ming Zuxun, a set of published dynastic instructions; this failed when his teenage successor, the Jianwen Emperor, attempted to curtail his uncles' power, prompting the Jingnan Campaign, an uprising that placed the Prince of Yan upon the throne as the Yongle Emperor in 1402.
The Yongle Emperor established Yan as a secondary capital and renamed it Beijing, constructed the Forbidden City, restored the Grand Canal and the primacy of the imperial examinations in official appointments. He rewarded his eunuch supporters and employed them as a counterweight against the Confucian scholar-bureaucrats. One, Zheng He, led seven enormous voyages of exploration into the Indian Ocean as far as Arabia and the eastern coasts of Africa; the rise of new emperors and new factions diminished such extravagances. The imperial navy was allowed to fall into disrepair while forced labor constructed the Liaodong palisade and connected and fortified the Great Wall of China into its modern form. Wide-ranging censuses of the entire empire were conducted decennially, but the desire to avoid labor and taxes and the difficulty of storing and reviewing the enormous archives at Nanjing hampered accurate figures. Estimates for the late-Ming population vary from 160 to 200 million, but necessary revenues were squeezed out of smaller and smaller numbers of farmers as more disappeared from the official records or "donated" their lands to tax-exempt eunuchs or temples.
Haijin laws intended to protect the coasts from "Japanese" pirates instead turned many into smugglers and pirates themselves. By the 16th century, the expansion of European trade – albeit restricted to islands near Guangzhou like Macau – spread the Columbian Exchange of crops and animals into China, introducing chili peppers to Sichuan cuisine and productive corn and potatoes, which diminished famines and spurred population growth; the growth of Portuguese and Dutch trade created new demand for Chinese products and produced a massive influx of Japanese and American silver. This abundance of specie remonetized the Ming economy, whose paper money had suffered repeated hyperinflation and was no longer trusted. While traditional Confucians opposed such a prominent role for commerce and the newly rich it created, the heterodoxy introduced by Wang Yangming permitted a more accommodating attitude. Zhang Juzheng's successful reforms proved devastating when a slowdown in agriculture produced by the Little Ice Age joined changes in Japanese and Spanish policy that cut off the supply of silver now necessary for farmers to be able to pay their taxes.
Combined with crop failure and epidemic, the dynasty collapsed before the rebel leader Li Zicheng, defeated by the Manchu-led Eight Banner armies who founded the Qing dynasty. The Mongol-led Yuan dynasty ruled before the establishment of the Ming dynasty. Explanations for the demise of the Yuan include institutionalized ethnic discrimination against Han Chinese that stirred resentment and rebellion, overtaxation of areas hard-hit by inflation, massive flooding of the Yellow River as a result of the abandonment of irrigation projects. Agriculture and the economy were in shambles, rebellion broke out among the hundreds of thousands of peasants called upon to work on repairing the dykes of the Yellow River. A number of Han Chinese groups revolted, including the Red Turbans in 1351; the Red Turbans were affiliated with a Buddhist secret society. Zhu Yuanzhang was a penniless peasant and Buddhist monk who joined the Red Turbans in 1352. In 1356, Zhu's rebel force captured the city of Nanjing, which he would establish as the capital of the Ming dynasty.
With the Yuan dynasty crumbling, competing rebel groups began fighting for control of the country and thus the right to establish a new dynasty. In 1363, Zhu Yuanzhang eliminated his archrival and leader of the rebel Han faction, Chen Youliang, in the Battle of Lake Poyang, arguably the largest naval battle in history. Known for its ambitious use of fire ships, Zhu's force of 200,000 Ming sailors were able to defeat a Han rebel force over triple their size, claimed to be 650,000-strong; the victory destroyed the last opposing rebel faction, leaving Zhu Yuanzhang in uncontested control of the bountiful Yangtze River Valley and cementing his power in the south. After the dynastic head of the Red Turbans suspiciously died in 1367 while a guest of Zhu, there was no one left, remotely capable of contesting his march to the throne, he made his imperial ambitions known by sending an army toward the Yuan capital Dadu in 1368; the las
Omaha is the largest city in the state of Nebraska and the county seat of Douglas County. Omaha is located in the Midwestern United States on the Missouri River, about 10 miles north of the mouth of the Platte River; the nation's 40th-largest city, Omaha's 2018 estimated population was 466,061. Omaha is the anchor of the bi-state Omaha-Council Bluffs metropolitan area; the Omaha Metropolitan Area is the 59th largest in the United States, with an estimated population of 944,316. The Omaha-Council Bluffs-Fremont, NE-IA Combined Statistical Area encompasses the Omaha-Council Bluffs MSA as well as the separate Fremont, NE Micropolitan Statistical Area, which consists of the entirety of Dodge County, Nebraska; the total population of the CSA was 970,023 based on 2017 estimates. 1.3 million people reside within the Greater Omaha area, within a 50 mi radius of Downtown Omaha. Omaha's pioneer period began in 1854, when the city was founded by speculators from neighboring Council Bluffs, Iowa; the city was founded along the Missouri River, a crossing called Lone Tree Ferry earned the city its nickname, the "Gateway to the West".
Omaha introduced this new West to the world in 1898, when it played host to the World's Fair, dubbed the Trans-Mississippi Exposition. During the 19th century, Omaha's central location in the United States spurred the city to become an important national transportation hub. Throughout the rest of the 19th century, the transportation and jobbing sectors were important in the city, along with its railroads and breweries. In the 20th century, the Omaha Stockyards, once the world's largest, its meatpacking plants gained international prominence. Today, Omaha is the home to the headquarters of four Fortune 500 companies: mega-conglomerate Berkshire Hathaway. Berkshire Hathaway is headed by local investor Warren Buffett, one of the richest people in the world, according to a decade's worth of Forbes Magazine rankings, some of which have ranked him as high as No. 1. Omaha is the home to five Fortune 1000 headquarters: Green Plains Renewable Energy, TD Ameritrade, Valmont Industries, Werner Enterprises, West Corporation.
Headquartered in Omaha are the following: First National Bank of Omaha, the largest held bank in the United States. Notable modern Omaha inventions include the following: the bobby pin and the "pink hair curler" created at Omaha's Tip Top Products. S. at Omaha's KOWH Radio. Various Native American tribes had lived in the land that became Omaha, including since the 17th century, the Omaha and Ponca, Dhegian-Siouan-language people who had originated in the lower Ohio River valley and migrated west by the early 17th century; the word Omaha means "Dwellers on the bluff". In 1804 the Lewis and Clark Expedition passed by the riverbanks where the city of Omaha would be built. Between July 30 and August 3, 1804, members of the expedition, including Meriwether Lewis and William Clark, met with Oto and Missouria tribal leaders at the Council Bluff at a point about 20 miles north of present-day Omaha. South of that area, Americans built several fur trading outposts in succeeding years, including Fort Lisa in 1812.
There was fierce competition among fur traders until John Jacob Astor created the monopoly of the American Fur Company. The Mormons built a town called Cutler's Park in the area in 1846. While it was temporary, the settlement provided the basis for further development in the future. Through 26 separate treaties with the United States federal government, Native American tribes in Nebraska ceded the lands constituting the state; the treaty and cession involving the Omaha area occurred in 1854 when the Omaha Tribe ceded most of east-central Nebraska. Logan Fontenelle, an interpreter for the Omaha and signatory to the 1854 treaty, played an essential role in those proceedings. Before it was legal to claim land in Indian Country, William D. Brown was operating the Lone Tree Ferry to bring settlers from Council Bluffs, Iowa to the area that became Omaha. Brown is credited as having the first vision for a city where Omaha now sits; the passage of the Kansas–Nebraska Act in 1854 was presaged by the staking out of claims around the area to become Omaha by residents from neighboring Council Bluffs.
On July 4, 1854, the city was informally established at a picnic on Capital Hill, current site of Omaha Central High School. Soon after, the Omaha Claim Club was formed to provide vigilante justice for claim jumpers and others who infringed on the land of many of the city's founding fathers; some of this land, which now wraps aro
An estuary is a enclosed coastal body of brackish water with one or more rivers or streams flowing into it, with a free connection to the open sea. Estuaries form a transition zone between river environments and maritime environments, they are subject both to marine influences—such as tides and the influx of saline water—and to riverine influences—such as flows of fresh water and sediment. The mixing of sea water and fresh water provide high levels of nutrients both in the water column and in sediment, making estuaries among the most productive natural habitats in the world. Most existing estuaries formed during the Holocene epoch with the flooding of river-eroded or glacially scoured valleys when the sea level began to rise about 10,000–12,000 years ago. Estuaries are classified according to their geomorphological features or to water-circulation patterns, they can have many different names, such as bays, lagoons, inlets, or sounds, although some of these water bodies do not meet the above definition of an estuary and may be saline.
The banks of many estuaries are amongst the most populated areas of the world, with about 60% of the world's population living along estuaries and the coast. As a result, many estuaries suffer degradation from a variety of factors including: sedimentation from soil erosion from deforestation and other poor farming practices; the word "estuary" is derived from the Latin word aestuarium meaning tidal inlet of the sea, which in itself is derived from the term aestus, meaning tide. There have been many definitions proposed to describe an estuary; the most accepted definition is: "a semi-enclosed coastal body of water, which has a free connection with the open sea, within which sea water is measurably diluted with freshwater derived from land drainage". However, this definition excludes a number of coastal water bodies such as coastal lagoons and brackish seas. A more comprehensive definition of an estuary is "a semi-enclosed body of water connected to the sea as far as the tidal limit or the salt intrusion limit and receiving freshwater runoff.
This broad definition includes fjords, river mouths, tidal creeks. An estuary is a dynamic ecosystem having a connection to the open sea through which the sea water enters with the rhythm of the tides; the sea water entering the estuary streams. The pattern of dilution varies between different estuaries and depends on the volume of fresh water, the tidal range, the extent of evaporation of the water in the estuary. Drowned river valleys are known as coastal plain estuaries. In places where the sea level is rising relative to the land, sea water progressively penetrates into river valleys and the topography of the estuary remains similar to that of a river valley; this is the most common type of estuary in temperate climates. Well-studied estuaries include the Severn Estuary in the United Kingdom and the Ems Dollard along the Dutch-German border; the width-to-depth ratio of these estuaries is large, appearing wedge-shaped in the inner part and broadening and deepening seaward. Water depths exceed 30 m.
Examples of this type of estuary in the U. S. are the Hudson River, Chesapeake Bay, Delaware Bay along the Mid-Atlantic coast, Galveston Bay and Tampa Bay along the Gulf Coast. Bar-built estuaries are found in place where the deposition of sediment has kept pace with rising sea level so that the estuaries are shallow and separated from the sea by sand spits or barrier islands, they are common in tropical and subtropical locations. These estuaries are semi-isolated from ocean waters by barrier beaches. Formation of barrier beaches encloses the estuary, with only narrow inlets allowing contact with the ocean waters. Bar-built estuaries develop on sloping plains located along tectonically stable edges of continents and marginal sea coasts, they are extensive along the Atlantic and Gulf coasts of the U. S. in areas with active coastal deposition of sediments and where tidal ranges are less than 4 m. The barrier beaches that enclose bar-built estuaries have been developed in several ways: building up of offshore bars by wave action, in which sand from the sea floor is deposited in elongated bars parallel to the shoreline, reworking of sediment discharge from rivers by wave and wind action into beaches, overwash flats, dunes, engulfment of mainland beach ridges due to sea level rise and resulting in the breaching of the ridges and flooding of the coastal lowlands, forming shallow lagoons, elongation of barrier spits from the erosion of headlands due to the action of longshore currents, with the spits growing in the direction of the littoral drift.
Barrier beaches form in shallow water and are parallel to the shoreline, resulting in long, narrow estuaries. The average water depth is less than 5 m, exceeds 10 m. Examples of bar-built estuaries are Barnegat Bay, New Jersey. Fjords were formed where pleistocene glaciers deepened and widened existing river valleys so that they become U-shaped in cross s
World War I
World War I known as the First World War or the Great War, was a global war originating in Europe that lasted from 28 July 1914 to 11 November 1918. Contemporaneously described as "the war to end all wars", it led to the mobilisation of more than 70 million military personnel, including 60 million Europeans, making it one of the largest wars in history, it is one of the deadliest conflicts in history, with an estimated nine million combatants and seven million civilian deaths as a direct result of the war, while resulting genocides and the 1918 influenza pandemic caused another 50 to 100 million deaths worldwide. On 28 June 1914, Gavrilo Princip, a Bosnian Serb Yugoslav nationalist, assassinated the Austro-Hungarian heir Archduke Franz Ferdinand in Sarajevo, leading to the July Crisis. In response, on 23 July Austria-Hungary issued an ultimatum to Serbia. Serbia's reply failed to satisfy the Austrians, the two moved to a war footing. A network of interlocking alliances enlarged the crisis from a bilateral issue in the Balkans to one involving most of Europe.
By July 1914, the great powers of Europe were divided into two coalitions: the Triple Entente—consisting of France and Britain—and the Triple Alliance of Germany, Austria-Hungary and Italy. Russia felt it necessary to back Serbia and, after Austria-Hungary shelled the Serbian capital of Belgrade on the 28th, partial mobilisation was approved. General Russian mobilisation was announced on the evening of 30 July; when Russia failed to comply, Germany declared war on 1 August in support of Austria-Hungary, with Austria-Hungary following suit on 6th. German strategy for a war on two fronts against France and Russia was to concentrate the bulk of its army in the West to defeat France within four weeks shift forces to the East before Russia could mobilise. On 2 August, Germany demanded free passage through Belgium, an essential element in achieving a quick victory over France; when this was refused, German forces invaded Belgium on 3 August and declared war on France the same day. On 12 August and France declared war on Austria-Hungary.
In November 1914, the Ottoman Empire entered the war on the side of the Alliance, opening fronts in the Caucasus and the Sinai Peninsula. The war was fought in and drew upon each power's colonial empire as well, spreading the conflict to Africa and across the globe; the Entente and its allies would become known as the Allied Powers, while the grouping of Austria-Hungary and their allies would become known as the Central Powers. The German advance into France was halted at the Battle of the Marne and by the end of 1914, the Western Front settled into a battle of attrition, marked by a long series of trench lines that changed little until 1917. In 1915, Italy opened a front in the Alps. Bulgaria joined the Central Powers in 1915 and Greece joined the Allies in 1917, expanding the war in the Balkans; the United States remained neutral, although by doing nothing to prevent the Allies from procuring American supplies whilst the Allied blockade prevented the Germans from doing the same the U. S. became an important supplier of war material to the Allies.
After the sinking of American merchant ships by German submarines, the revelation that the Germans were trying to incite Mexico to make war on the United States, the U. S. declared war on Germany on 6 April 1917. Trained American forces would not begin arriving at the front in large numbers until mid-1918, but the American Expeditionary Force would reach some two million troops. Though Serbia was defeated in 1915, Romania joined the Allied Powers in 1916 only to be defeated in 1917, none of the great powers were knocked out of the war until 1918; the 1917 February Revolution in Russia replaced the Tsarist autocracy with the Provisional Government, but continuing discontent at the cost of the war led to the October Revolution, the creation of the Soviet Socialist Republic, the signing of the Treaty of Brest-Litovsk by the new government in March 1918, ending Russia's involvement in the war. This allowed the transfer of large numbers of German troops from the East to the Western Front, resulting in the German March 1918 Offensive.
This offensive was successful, but the Allies rallied and drove the Germans back in their Hundred Days Offensive. Bulgaria was the first Central Power to sign an armistice—the Armistice of Salonica on 29 September 1918. On 30 October, the Ottoman Empire capitulated. On 4 November, the Austro-Hungarian empire agreed to the Armistice of Villa Giusti after being decisively defeated by Italy in the Battle of Vittorio Veneto. With its allies defeated, revolution at home, the military no longer willing to fight, Kaiser Wilhelm abdicated on 9 November and Germany signed an armistice on 11 November 1918. World War I was a significant turning point in the political, cultural and social climate of the world; the war and its immediate aftermath sparked numerous uprisings. The Big Four (Britain, the United States, It