Every year on Nov. 11, the United States marks Veterans Day, celebrating people who have fought in the U.S. military throughout the nation’s history.

In 1954, President Dwight Eisenhower declared that Nov. 11 would be the first Veterans Day honoring those Americans.

But Nov. 11 was already celebrated prior to that for a range of reasons.

The holiday was originally marked as Armistice Day in the U.S. and around the world, with memorials and celebrations to mark the end of fighting in World War I. While the war officially ended when the Treaty of Versailles was signed on June 28, 1919, cessation of hostilities actually took place on the 11th hour, of the 11th day, of the 11 month, in 1918. Nov. 11, 1918, is regarded as the end of “the war to end all wars.”