Veterans Day is an American holiday dedicated to honoring its military veterans. Here is the background for why America celebrates Veterans Day on November 11th of each year.

In 1918, on the 11th hour of the 11th day of the 11th month, an armistice was declared between the Allied forces and Germany in World War I. The following year, many countries celebrated November 11th as Armistice Day.
In the United States, President Woodrow Wilson declared November 11, 1919 as the first national commemoration of Armistice Day. Throughout America, there were parades, picnics, and public speeches, as well as a moment of prayer in schools and businesses at 11:00 a.m.
Two years later, on November 11, 1921, an unidentified American soldier killed in World War I was laid to rest at the Tomb of the Unknown Soldier in Arlington National Cemetery, just outside Washington, DC. President Warren G. Harding presided over the ceremony.

On June 4, 1926, the U.S. Congress passed a resolution that the “recurring anniversary of [November 11, 1918] should be commemorated with thanksgiving and prayer and exercises designed to perpetuate peace through good will and mutual understanding between nations.” Congress also resolved that the president should issue an annual proclamation calling for the observance of Armistice Day.
On May 13, 1938, Congress made November 11th an official federal holiday, “dedicated to the cause of world peace and to be hereafter celebrated and known as Armistice Day.” As a formal matter, there is no such thing as a national holiday in the U.S. Each state retains the right to designate their own holidays, and the federal government can only designate holidays for federal employees and the District of Columbia. Historically, however, most states have followed the federal list of holidays.
In the aftermath of World War II and the Korean War, there was a movement by military service organizations to honor American veterans more broadly. As a result, in 1954, the U.S. Congress amended the 1938 law establishing Armistice Day, by changing the word “Armistice” to “Veterans.” President Dwight D. Eisenhower signed the amendment on June 1, 1954, and from that day forward, November 11th was known as Veterans Day – a day to honor American veterans of all wars.