World War I was a global conflict originating in Europe. It lasted from July 28, 1914 to November 11, 1918. It was one of the largest and deadliest wars up to that point in history, with an estimated 9 million combatants and 7 million civilian deaths. The assassination of Austria’s Archduke Ferdinand and his wife by a Serbian nationalist set off a chain of events. A web of entangling alliances pulled country after country into war. On April 6, 1917, the U.S. joined France, Britain, Russia, Italy, and Japan (Allied Powers) against the Central Powers (mainly Germany, Austria-Hungary, and Turkey). Germany surrendered on November 11, 1918.