The group that organized today's event put this special message on their website "The roots of our parade originate in an Act of Congress - Act (52 Stat. 351; 5 U. S. Code, Sec. 87a) approved May 13, 1938, made the 11th of November and originally called Armistice Day. 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."
You can visit their website here.