The U.S. Army's birthday is celebrated on June 14th each year. This date marks the founding of the Army by the Second Continental Congress on June 14, 1775, when it authorized the enlistment of riflemen to serve the United Colonies during the Revolutionary War. Therefore, the Army's "0th" birthday—i.e., the actual founding day—was June 14, 1775. In 2025, the Army celebrated its 250th birthday on June 14th, confirming this foundational date. So, the Army's 0th birthday was on June 14, 1775. This date is regarded as America's first national institution and the starting point of the U.S. Army as a unified military force.