The Allied powers signed a cease-fire agreement with Germany at Rethondes, France on November 11, 1918, bringing World War I to a close. Between the wars, November 11 was commemorated as Armistice Day in the United States, Great Britain, and France. After World War II, the holiday was recognized as a day of tribute to veterans of both world wars. Beginning in 1954, the United States designated November 11 as Veterans Day to honor veterans of all U.S. wars.
Source: Library of Congress
Official Department of Veterans Affairs Veterans Day website.