World War I – known at the time as “The Great War” - officially ended when the Treaty of Versailles was signed on June 28, 1919, in the Palace of Versailles outside the town of Versailles, France. However, fighting ceased seven months earlier when an armistice, or temporary cessation of hostilities, between the Allied nations and Germany went into effect on the eleventh hour of the eleventh day of the eleventh month. For that reason, November 11, 1918, is generally regarded as the end of “the war to end all wars.”
In November 1919, President Wilson proclaimed November 11 as the first commemoration of Armistice Day with the following words: "To us in America, the reflections of Armistice Day will be filled with solemn pride in the heroism of those who died in the country’s service and with gratitude for the victory, both because of the thing from which it has freed us and because of the opportunity it has given America to show her sympathy with peace and justice in the councils of the nations…"
The United States Congress officially recognized the end of World War I when it passed a concurrent resolution on June 4, 1926.
An Act (52 Stat. 351; 5 U. S. Code, Sec. 87a) approved May 13, 1938, made the 11th of November in each year a legal holiday—a day to be dedicated to the cause of world peace and to be thereafter celebrated and known as "Armistice Day." Armistice Day was primarily a day set aside to honor veterans of World War I, but in 1954, after World War II had required the greatest mobilization of soldiers, sailors, Marines and airmen in the Nation’s history; after American forces had fought aggression in Korea, the 83rd Congress, at the urging of the veterans service organizations, amended the Act of 1938 by striking out the word "Armistice" and inserting in its place the word "Veterans." With the approval of this legislation (Public Law 380) on June 1, 1954, November 11th became a day to honor American veterans of all wars.
Veterans Day continues to be observed on November 11, regardless of what day of the week on which it falls. The restoration of the observance of Veterans Day to November 11 not only preserves the historical significance of the date, but helps focus attention on the important purpose of Veterans Day: A celebration to honor America's veterans for their patriotism, love of country, and willingness to serve and sacrifice for the common good.
https://www.va.gov/opa/vetsday/vetdayhistory.asp
The Veterans Day National Ceremony is held each year on November 11th at Arlington National Cemetery . The ceremony commences precisely at 11:00 a.m. with a wreath laying at the Tomb of the Unknowns and continues inside the Memorial Amphitheater with a parade of colors by veterans' organizations and remarks from dignitaries. The ceremony is intended to honor and thank all who served in the United States Armed Forces.
https://www.va.gov/opa/vetsday/
Veterans Day is a time for us to pay our respects to those who have served. For one day, we stand united in respect for you, our veterans.
This holiday started as a day to reflect upon the heroism of those who died in our country's service and was originally called Armistice Day. It fell on Nov. 11 because that is the anniversary of the signing of the Armistice that ended World War I. However, in 1954, the holiday was changed to "Veterans Day" in order to account for all veterans in all wars.
Learn about the history of Veterans Day
We celebrate and honor America's veterans for their patriotism, love of country and willingness to serve and sacrifice for the common good.
https://www.military.com/veterans-day
Veterans Day honors all of those who have served the country in war or peace — dead or alive — although it’s largely intended to thank living veterans for their sacrifices.
https://www.defense.gov/Explore/Features/story/Article/1675470/5-facts-to-know-about-veterans-day/