Armistice Day.

• Veterans Day in the United States originated as Armistice Day, established to mark the armistice ending World War I on November 11, 1918.

• In 1954, following World War II and the Korean War, the holiday was renamed Veterans Day to honor all American veterans, not just those who served in WWI.

• The date was briefly moved to the fourth Monday in October by the Uniform Monday Holiday Act, but was restored to November 11 starting in 1978 to preserve the historical significance of the WWI armistice.

If you’d like, I can pull more sources or provide a brief timeline of the key changes over the decades.