Bronze is an alloy consisting of copper with about 12–12.5% tin and with the addition of other metals and sometimes non-metals or metalloids such as arsenic, phosphorus or silicon. These additions produce a range of alloys that may be harder than copper alone, or have other useful properties, such as stiffness, ductility, or machinability; the archeological period in which bronze was the hardest metal in widespread use is known as the Bronze Age. The beginning of the Bronze Age in India and western Eurasia is conventionally dated to the mid-4th millennium BC, to the early 2nd millennium BC in China; the Bronze Age was followed by the Iron Age starting from about 1300 BC and reaching most of Eurasia by about 500 BC, although bronze continued to be much more used than it is in modern times. Because historical pieces were made of brasses and bronzes with different compositions, modern museum and scholarly descriptions of older objects use the more inclusive term "copper alloy" instead. There are two basic theories as to the origin of the word.
Romance theoryThe Romance theory holds that the word bronze was borrowed from French bronze, itself borrowed from Italian bronzo "bell metal, brass" from either, bróntion, back-formation from Byzantine Greek brontēsíon from Brentḗsion ‘Brindisi’, reputed for its bronze. Proto-Slavic theoryThe Proto-Slavic theory reflects the philological issue that in the most of Slavonic languages word "bronza" corresponds to "war metal" while at the early stages of the Bronze working it was used exclusively for military purposes; the discovery of bronze enabled people to create metal objects which were harder and more durable than possible. Bronze tools, weapons and building materials such as decorative tiles were harder and more durable than their stone and copper predecessors. Bronze was made out of copper and arsenic, forming arsenic bronze, or from or artificially mixed ores of copper and arsenic, with the earliest artifacts so far known coming from the Iranian plateau in the 5th millennium BC, it was only that tin was used, becoming the major non-copper ingredient of bronze in the late 3rd millennium BC.
Tin bronze was superior to arsenic bronze in that the alloying process could be more controlled, the resulting alloy was stronger and easier to cast. Unlike arsenic, metallic tin and fumes from tin refining are not toxic; the earliest tin-alloy bronze dates to 4500 BC in a Vinča culture site in Pločnik. Other early examples date to the late 4th millennium BC in Egypt and some ancient sites in China and Mesopotamia. Ores of copper and the far rarer tin are not found together, so serious bronze work has always involved trade. Tin sources and trade in ancient times had a major influence on the development of cultures. In Europe, a major source of tin was the British deposits of ore in Cornwall, which were traded as far as Phoenicia in the eastern Mediterranean. In many parts of the world, large hoards of bronze artifacts are found, suggesting that bronze represented a store of value and an indicator of social status. In Europe, large hoards of bronze tools socketed axes, are found, which show no signs of wear.
With Chinese ritual bronzes, which are documented in the inscriptions they carry and from other sources, the case is clear. These were made in enormous quantities for elite burials, used by the living for ritual offerings. Though bronze is harder than wrought iron, with Vickers hardness of 60–258 vs. 30–80, the Bronze Age gave way to the Iron Age after a serious disruption of the tin trade: the population migrations of around 1200–1100 BC reduced the shipping of tin around the Mediterranean and from Britain, limiting supplies and raising prices. As the art of working in iron improved, iron improved in quality; as cultures advanced from hand-wrought iron to machine-forged iron, blacksmiths learned how to make steel. Steel holds a sharper edge longer. Bronze was still used during the Iron Age, has continued in use for many purposes to the modern day. There are many different bronze alloys, but modern bronze is 88% copper and 12% tin. Alpha bronze consists of the alpha solid solution of tin in copper.
Alpha bronze alloys of 4–5% tin are used to make coins, springs and blades. Historical "bronzes" are variable in composition, as most metalworkers used whatever scrap was on hand; the proportions of this mixture suggests. The Benin Bronzes are in fact brass, the Romanesque Baptismal font at St Bartholomew's Church, Liège is described as both bronze and brass. In the Bronze Age, two forms of bronze were used: "classic bronze", about 10% tin, was used in
Abraham Lincoln (1920 statue)
Abraham Lincoln is a colossal seated figure of United States President Abraham Lincoln sculpted by Daniel Chester French and carved by the Piccirilli Brothers. It is situated in the Lincoln Memorial, on the National Mall, Washington, D. C. USA, was unveiled in 1922. Stylistically, the work follows in the Beaux Arts and American Renaissance traditions; the 170-ton statue is composed of 28 blocks of white Georgia marble and rises 30 feet from the floor, including the 19-foot seated figure upon an 11-foot high pedestal. The figure of Lincoln gazes directly ahead and down with an expression of gravity and solemnity, his frock coat is unbuttoned, a large United States flag is draped over the chair back and sides. French paid special attention to Lincoln's expressive hands, which rest on the enormous arms of a circular, ceremonial chair, the fronts of which bear fasces, emblems of authority from Roman antiquity. French used casts of his own fingers to achieve the correct placement. Daniel Chester French was selected in 1914 by the Lincoln Memorial Committee to create a Lincoln statue as part of the memorial to be designed by architect Henry Bacon.
French was famous for his Minute Man statue in Concord, Massachusetts. He was the personal choice of Bacon, collaborating with him for nearly 25 years. French resigned his chairmanship of the Fine Arts Commission in Washington, D. C.—a group affiliated with the memorial's design and creation—and commenced work in December. French had created a major memorial statue of Lincoln—this one standing—for the Nebraska State Capitol in Lincoln, Nebraska, his previous studies of Lincoln—which included biographies, a life mask of Lincoln by Leonard Volk done in 1860—had prepared him for the challenging task of the larger statue. For the national memorial, he and Bacon decided that a large seated figure would be most appropriate. French started with a small clay study and subsequently created several plaster models, each time making subtle changes in the figure's pose or setting, he placed the President not in an ordinary 19th-century seat, but in a classical chair including fasces, a Roman symbol of authority, to convey that the subject was an eminence for all the ages.
Three plaster models of the Lincoln statue are at French's Chesterwood Studio, a National Trust Historic Site in Stockbridge, including a plaster sketch and a six-foot plaster model. The second of French's plasters, created at Chesterwood in the summer of 1916 would be further enlarged and became the basis of the colossal marble; the work was to have been a 12-foot bronze image. To determine the optimum scale and size for the memorial statue French and Bacon took photographic enlargements of the statue to the memorial while it was still under construction. French's longtime collaborators, the firm of Piccirilli Brothers, were commissioned to do the carving of a much larger sculpture in marble from a quarry near Tate, Georgia, it took a full year for French's design to be transferred to the massive marble blocks. French provided finishing strokes in the carvers' studio in New York City and after the statue was assembled in the memorial on the National Mall in 1920. Lighting the statue was a particular problem.
In creating the work, French had understood that a large skylight would provide direct, natural illumination from overhead, but this was not included in the final plans. The horizontal light from the east caused Lincoln's facial features to appear flattened—making him appear to stare blankly, rather than wear a dignified expression—and highlighted his shins. French considered this a disaster. In the end, an arrangement of electric lights was devised to correct this situation; the work was unveiled at the memorial's formal dedication on May 30, 1922. A legend is that Lincoln is shown using sign language to represent his initials, with his left hand shaped to form an "A" and his right hand to form an "L"; the National Park Service denies the story. However, historian Gerald Prokopowicz writes that, while it is not clear that sculptor Daniel Chester French intended for Lincoln's hands to be formed into sign language versions of his initials, it is possible that French did intend it, because he was familiar with American Sign Language, he would have had a reason to do so, i.e. to pay tribute to Lincoln for having signed the federal legislation giving Gallaudet University, a university for the deaf, the authority to grant college degrees.
The National Geographic Society's publication, On This Spot: Pinpointing the Past in Washington, D. C. states that French had a son, deaf, the sculptor was familiar with sign language. Historian James A. Percoco has observed that, although there are no extant documents showing that French carved Lincoln's hands to represent the letters "A" and "L" in American Sign Language, "I think you can conclude that it's reasonable to have that kind of summation about the hands." Outdoor sculpture in Washington, D. C. Save Outdoor Sculpture Survey
National Academy of Design
The National Academy of Design is an honorary association of American artists, founded in New York City in 1825 by Samuel Morse, Asher Durand, Thomas Cole, Martin E. Thompson, Charles Cushing Wright, Ithiel Town, others "to promote the fine arts in America through instruction and exhibition." The original founders of the National Academy of Design were students of the American Academy of the Fine Arts. However, by 1825 the students of the American Academy felt a lack of support for teaching from the academy, its board composed of merchants and physicians, from its unsympathetic president, the painter John Trumbull. Samuel Morse and other students set about forming "the drawing association", to meet several times each week for the study of the art of design. Still, the association was viewed as a dependent organization of the American Academy, from which they felt neglected. An attempt was made to reconcile differences and maintain a single academy by appointing six of the artists from the association as directors of the American Academy.
When four of the nominees were not elected, the frustrated artists resolved to form a new academy and the National Academy of Design was born. Morse had been a student at the Royal Academy in London and emulated its structure and goals for the National Academy of Design. After three years and some tentative names, in 1828 the academy found its longstanding name "National Academy of Design", under which it was known for one and a half centuries. In 1997, newly appointed director Annette Blaugrund rebranded the institution as the "National Academy Museum and School of Fine Art", to reflect "a new spirit of integration incorporating the association of artists and school", to avoid confusion with the now differently understood term "design"; this change was reversed in 2017. 1825 The New York Drawing Association 1826 The National Academy of The Arts of Design 1828 The National Academy of Design 1997 The National Academy Museum and School of Fine Art 2017 The National Academy of Design The Academy occupied several locations in Manhattan over the years.
Notable among them was a building on Park Avenue and 23rd Street designed by architect P. B. Wight and built 1863–1865 in a Venetian Gothic style modeled on the Doge's Palace in Venice. Another location was at West 109th Amsterdam Avenue. Since 1942 the academy has occupied a mansion at Fifth Avenue and Eighty-ninth Street, the former home of sculptor Anna Hyatt Huntington and philanthropist Archer M. Huntington, who donated the house in 1940; the academy is a professional honorary organization, with a museum. One cannot apply for membership, which since 1994, after many changes in numbers, is limited to 450 American artists and architects. Instead, members are elected by their peers on the basis of recognized excellence. Full members of the National Academy are identified by the post-nominal "NA", associates by "ANA"; the school offers studio instruction, master classes, intensive critiques, various workshops, lunchtime lectures. Scholarships are available; the museum houses a public collection of over 7,000 works of American art from the 19th, 20th, 21st centuries.
As of November 2018 the academy's Board of Governors consists of 18 board members, with Bruce Fowle as President and James Siena as Chairman of the Abbey Council. Maura Reilly serves as Executive Director since 2015. Among the teaching staff were numerous artists, including Will Hicok Low, who taught from 1889 to 1892; the famous American poet William Cullen Bryant gave lectures. Architect Alexander Jackson Davis taught at the academy. Painter Lemuel Wilmarth was the first full-time instructor. Silas Dustin was a curator; some of the Academy's better-known members include: American Watercolor Society Effects of the financial crisis of 2007–2009 on museums List of museums and cultural institutions in New York City Official website National Academy of Design at Google Cultural Institute
United States Capitol
The United States Capitol called the Capitol Building, is the home of the United States Congress and the seat of the legislative branch of the U. S. federal government. It is located on Capitol Hill at the eastern end of the National Mall in Washington, D. C. Though no longer at the geographic center of the Federal District, the Capitol forms the origin point for the District's street-numbering system and the District's four quadrants; the original building was completed in 1800 and was subsequently expanded with the addition of the massive dome, expanded chambers for the bicameral legislature, the House of Representatives in the south wing and the Senate in the north wing. Like the principal buildings of the executive and judicial branches, the Capitol is built in a distinctive neoclassical style and has a white exterior. Both its east and west elevations are formally referred to as fronts, though only the east front was intended for the reception of visitors and dignitaries. Prior to establishing the nation's capital in Washington, D.
C. the United States Congress and its predecessors had met in Philadelphia, New York City, a number of other locations. In September 1774, the First Continental Congress brought together delegates from the colonies in Philadelphia, followed by the Second Continental Congress, which met from May 1775 to March 1781. After adopting the Articles of Confederation in York, the Congress of the Confederation was formed and convened in Philadelphia from March 1781 until June 1783, when a mob of angry soldiers converged upon Independence Hall, demanding payment for their service during the American Revolutionary War. Congress requested that John Dickinson, the Governor of Pennsylvania, call up the militia to defend Congress from attacks by the protesters. In what became known as the Pennsylvania Mutiny of 1783, Dickinson sympathized with the protesters and refused to remove them from Philadelphia; as a result, Congress was forced to flee to Princeton, New Jersey, on June 21, 1783, met in Annapolis and Trenton, New Jersey, before ending up in New York City.
The United States Congress was established upon ratification of the United States Constitution and formally began on March 4, 1789. New York City remained home to Congress until July 1790, when the Residence Act was passed to pave the way for a permanent capital; the decision of where to locate the capital was contentious, but Alexander Hamilton helped broker a compromise in which the federal government would take on war debt incurred during the American Revolutionary War, in exchange for support from northern states for locating the capital along the Potomac River. As part of the legislation, Philadelphia was chosen as a temporary capital for ten years, until the nation's capital in Washington, D. C. would be ready. Pierre Charles L'Enfant was given the task of creating the city plan for the new capital city. L'Enfant chose Jenkin's Hill as the site for the "Congress House", with a "grand avenue" connecting it with the President's House, a public space containing a broader "grand avenue" stretching westward to the Potomac River.
In reviewing L'Enfant's plan, Thomas Jefferson insisted the legislative building be called the "Capitol" rather than "Congress House". The word "Capitol" comes from Latin and is associated with the Temple of Jupiter Optimus Maximus on Capitoline Hill, one of the seven hills of Rome; the connection between the two is not, crystal clear. In addition to coming up with a city plan, L'Enfant had been tasked with designing the Capitol and President's House; the word "capitol" has since been adopted, following the example of the United States Capitol, in many jurisdictions for other government buildings, for instance the "capitols" in the individual capitals of the states of the United States. This, in turn, has led to frequent misspellings of "capitol" and "capital"; the former refers to a building. In spring 1792, United States Secretary of State Thomas Jefferson proposed a design competition to solicit designs for the Capitol and the "President's House", set a four-month deadline; the prize for the competition was a lot in the Federal City.
At least ten individuals submitted designs for the Capitol. The most promising of the submissions was by a trained French architect. However, Hallet's designs were overly fancy, with too much French influence, were deemed too costly. A late entry by amateur architect William Thornton was submitted on January 31, 1793, to much praise for its "Grandeur and Beauty" by Washington, along with praise from Thomas Jefferson. Thornton was inspired by the east front of the Louvre, as well as the Paris Pantheon for the center portion of the design. Thornton's design was approved in a letter dated April 5, 1793, from Washington, Thornton served as the first Architect of the Capitol. In an effort to console Hallet, the commissioners appointed him to review Thornton's plans, develop cost estimates, serve as superintendent of construction. Hallet proceeded to pick apart and make drastic changes
World War II Victory Medal (United States)
The World War II Victory Medal is a service medal of the United States military, established by an Act of Congress on 6 July 1945 and promulgated by Section V, War Department Bulletin 12, 1945. The corresponding medal from World War I is the World War I Victory Medal; the World War II Victory Medal was first issued as a service ribbon referred to as the “Victory Ribbon.” The World War II Victory Medal was established by an Act of Congress on 6 July 1945 and promulgated by Section V, War Department Bulletin 12, 1945. The medal was designed by Mr. Thomas H. Jones and approved by the Secretary of War on 5 February 1946, it did not transition from a ribbon to a full medal until after World War II had ended. The Congressional authorization for the medal specified that it was to be awarded to any member of the United States military, including members of the armed forces of the Government of the Philippine Islands, who served on active duty, or as a reservist, between 7 December 1941 and 31 December 1946.
On 8 August 1946, the separate Merchant Marine World War II Victory Medal was established for members of the United States Merchant Marine who served during World War II. The medal is awarded for service between 7 December 1941 and 31 December 1946, both dates inclusive; the National Personnel Records Center has reported some cases of service members receiving the award for a few days of service. As the Second World War ended on 2 September 1945, there may be cases of service members who had enlisted, entered officer candidate school, or had been a cadet or midshipman at the U. S. Military Academy, the U. S. Naval Academy or the U. S. Coast Guard Academy between 3 September 1945 and any date in 1946, receiving the medal without having been a veteran of World War II; the reason for this late date is that President Harry S. Truman did not declare an official end of hostilities until the last day of 1946; as every member of the United States Armed Forces who served from December 7, 1941 to December 31, 1946 was eligible for the medal, there were over 12 million eligible recipients, making the World War II Victory Medal one of the most awarded decorations of the United States military.
The bronze medal is 1 4⁄8 inches in width. The obverse is a figure of Liberation standing full length with head turned to dexter looking to the dawn of a new day, right foot resting on a war god’s helmet with the hilt of a broken sword in the right hand and the broken blade in the left hand, the inscription WORLD WAR II placed below the center. On the reverse are inscriptions for the Four Freedoms: FREEDOM FROM FEAR AND WANT and FREEDOM OF SPEECH AND RELIGION separated by a palm branch, all within a circle composed of the words UNITED STATES OF AMERICA 1941 1945; the suspension and service ribbon of the medal is 1 3⁄8 inches wide and consists of the following stripes: 3⁄8 inch double rainbow in juxtaposition. The rainbow on each side of the ribbon is a miniature of the pattern used in the World War I Victory Medal. Although the World War I Victory Medal included clasps, the World War II Victory Medal did not; this was. Awards and decorations of the United States military Merchant Marine World War II Victory Medal United States Statutes at Large.
Vol. 59. Washington, DC: Office of the Federal Register. 1946. P. 461. Code of Federal Regulations. Washington, DC: Office of the Federal Register. 2008. 32CFR578.47. Retrieved 4 June 2009. NavPers 15,790: Navy and Marine Corps Awards Manual. Washington, DC: Department of the Navy. 1960. P. 161. OCLC 45726498. Retrieved 4 June 2009. MIL-DTL-3943/237A: Detail Specification Sheet — Medal, World War II Victory. 15 August 2008. Retrieved 4 June 2009. MIL-DTL-11589/149E: Detail Specification Sheet — Ribbon, World War II Victory Medal. 15 September 1995. Retrieved 4 June 2009. "World War II Victory Medal". Fort Belvoir, Virginia: The Institute of Heraldry, U. S. Army. Archived from the original on September 9, 2009. Retrieved 4 June 2009
Columbia University is a private Ivy League research university in Upper Manhattan, New York City. Established in 1754, Columbia is the oldest institution of higher education in New York and the fifth-oldest institution of higher learning in the United States, it is one of nine colonial colleges founded prior to the Declaration of Independence, seven of which belong to the Ivy League. It has been ranked by numerous major education publications as among the top ten universities in the world. Columbia was established as King's College by royal charter of George II of Great Britain in reaction to the founding of Princeton University in New Jersey, it was renamed Columbia College in 1784 following the Revolutionary War and in 1787 was placed under a private board of trustees headed by former students Alexander Hamilton and John Jay. In 1896, the campus was moved from Madison Avenue to its current location in Morningside Heights and renamed Columbia University. Columbia scientists and scholars have played an important role in the development of notable scientific fields and breakthroughs including: brain-computer interface.
The Columbia University Physics Department has been affiliated with 33 Nobel Prize winners as alumni, faculty or research staff, the third most of any American institution behind MIT and Harvard. In addition, 22 Nobel Prize winners in Physiology and Medicine have been affiliated with Columbia, the third most of any American institution; the university's research efforts include the Lamont-Doherty Earth Observatory, Goddard Institute for Space Studies and accelerator laboratories with major technology firms such as IBM. Columbia is one of the fourteen founding members of the Association of American Universities and was the first school in the United States to grant the M. D. degree. The university administers the Pulitzer Prize annually. Columbia is organized into twenty schools, including three undergraduate schools and numerous graduate schools, it maintains research centers outside of the United States known as Columbia Global Centers. In 2018, Columbia's undergraduate acceptance rate was 5.1%, making it one of the most selective colleges in the United States, the second most selective in the Ivy League after Harvard.
Columbia is ranked as the 3rd best university in the United States by U. S. News & World Report behind Princeton and Harvard. In athletics, the Lions field varsity teams in 29 sports as a member of the NCAA Division I Ivy League conference; the university's endowment stood at $10.9 billion in 2018, among the largest of any academic institution. As of 2018, Columbia's alumni and affiliates include: five Founding Fathers of the United States — among them an author of the United States Constitution and co-author of the Declaration of Independence. S. presidents. Discussions regarding the founding of a college in the Province of New York began as early as 1704, at which time Colonel Lewis Morris wrote to the Society for the Propagation of the Gospel in Foreign Parts, the missionary arm of the Church of England, persuading the society that New York City was an ideal community in which to establish a college. However, it was not until the founding of the College of New Jersey across the Hudson River in New Jersey that the City of New York considered founding a college.
In 1746, an act was passed by the general assembly of New York to raise funds for the foundation of a new college. In 1751, the assembly appointed a commission of ten New York residents, seven of whom were members of the Church of England, to direct the funds accrued by the state lottery towards the foundation of a college. Classes were held in July 1754 and were presided over by the college's first president, Dr. Samuel Johnson. Dr. Johnson was the only instructor of the college's first class, which consisted of a mere eight students. Instruction was held in a new schoolhouse adjoining Trinity Church, located on what is now lower Broadway in Manhattan; the college was founded on October 31, 1754, as King's College by royal charter of King George II, making it the oldest institution of higher learning in the state of New York and the fifth oldest in the United States. In 1763, Dr. Johnson was succeeded in the presidency by Myles Cooper, a graduate of The Queen's College, an ardent Tory. In the charged political climate of the American Revolution, his chief opponent in discussions at the college was an undergraduate of the class of 1777, Alexander Hamilton.
The American Revolutionary War broke out in 1776, was catastrophic for the operation of King's College, which suspended instruction for eight years beginning in 1776 with the arrival of the Continental Army. The suspension continued through the military occupation of New York City by British troops until their departure in 1783; the college's library was looted and its sole building requisitioned for use as a military hospital first by American and British forces. Loyalists were forced to abandon their King's College in New York, seized by the rebels and renamed Columbia College; the Loyalists, led by Bishop Charles Inglis fled to Windsor, Nova Scotia, where the
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