World War I began in 1914 following the assassination of an Austrian archduke, and it grew out of the political and diplomatic entanglements of a Europe emerging from the 19th century. Japan, only recently engaging with the West, joined as well. Diplomatic machinations by the coalitions on both sides of the war in Europe sought to either draw in or keep out the United States, not yet a superpower on the international stage. At the time, the United States was wrapped up in the revolution in Mexico, and it was the uncertainties and instabilities in Mexico that would ultimately serve to draw the country into the European war.
The war was technologically different from those preceding it in Europe; armies made use of machine guns, airplanes, tanks, chemical weapons, telephones, zeppelins, new artillary, and other innovations. Horse cavalry became obsolete. The trenches, with barbed-wire laced no-man's land between, became symbols of the war. Navies made the first extensive use of submarines, and aircraft carriers were introduced on a limited basis.
The world emerged from the war changed; empires disappeared, borders were redrawn yet again, and nations reformed from the rubble. An influenza epidemic that began during the last year of the war killed millions worldwide. There were attempts to form an international body to prevent another world war, but the League of Nations never grew to the level of influence that the later United Nations would, partly due to the United States never joining.
America emerged from the war uncertain whether it wanted to move onto the world stage as a major player or to retreat back into its pervious isolationism. The spirit of the Monroe Doctrine had long kept the United States from getting entangled in European political affairs, and it was not until after the next world war that the country would accept its new, starring role.
National World War I Museum (located in Kansas City, MO)
World War I Prints and Photographs in the Library of Congress
World War I Resources from the British Library
Interactive WWI site by the Wall Street Journal
World War I Resources from West Point's Department of History
Historical Resources from the U.S. Army
World War I Images (Google Image Search)
Books about WWI from Project Gutenberg
Historical Sheet Music from Duke University Library
The World War I display is located in the showcase display area on the second floor, at the top of the stairs. The display features information on the war reported by The New York Times. Images are from microfilm, and quality varies based on the condition of the microfilm. Additional materials for the display have been drawn from archival photograph collections, the Library's own collections, and items on loan from private individuals.
If you're interested in more of The New York Times ' coverage of the war, the microfilm is available on the main floor of the Library. Indexes are available in the reference collection, REF AI21.N44. If you need assistance, just ask!