Originally, Veterans Day was called “Armistice Day,” and the date was chosen to commemorate the signing of the armistice with Germany that ended hostilities during World War I.
The armistice, signed on November 11th, 1918, did not officially end that war, however. That came on June 28th, 1919, with the signing of the Treaty of Versailles. On the other hand, since the U.S. never signed the Treaty of Versailles like the other Allies, one could say that for the U.S. at least, the November 11th armistice really did end the war.
At first, the focus of Armistice Day was on the veterans of World War I, though it was always meant to honor all veterans of foreign wars, who risked their lives on the battle field to secure the freedoms of all Americans. Over time, with the passing away of the World War I generation and the coming of new conflicts during World War II, the Korean War, and the Vietnam War, the focus on the 1918 Armistice was lost and the name of the holiday was changed. Additionally, today, Veterans Day is generally regarded as honoring all those who ever served in the U.S. Armed Force rather than only those who actually fought in a war.