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.
Another development took place in 1926, when Congress finally decided to declare that World War I was over. It was odd for this recognition of an existing reality to come seven years late, but without the U.S. agreeing to the Treaty of Versailles, there had been no official end to the war. Congress also made November 11th a day of prayer and thanksgiving and expressed a desire that the U.S. flag be on display during this day and that special ceremonies be held.
Finally, in 1938, Armistice Day became a permanent, official public holiday. Eerily enough, the holiday designed to honor World War I veterans became official only a few years before World War II arrived. The next stage in the history of Veterans Day came in 1954, when it received its present name. Congress made the change when pressed to do so by various private veterans organizations.
A debacle involving Veterans Day came in 1971, when Congress changed the date from November 11th to the fourth Monday in October. This led to chaos because many states refused to recognize the change. Some would be celebrating in November while others did so in October, and the resistance to the date change never broke down. Finally, the date was changed back to November 11th beginning in 1978.