On June 14, 1777, the Second Continental Congress adopted by resolution the official Flag of the United States with 13 stars and 13 stripes representing the thirteen British colonies that declared independence from Great Britain and became the first states in the Union.
Although Flag Day is not an official federal holiday, in 1916, Woodrow Wilson signed a proclamation making June 14 "Flag Day.”
On Flag Day, 1942, Franklin D. Roosevelt stated: “The belief in man, created free, in the image of God-is the crucial difference between ourselves and the enemies we face…God of the free…grant us victory over the tyrants who would enslave all free men.”
In August 1949, an Act of Congress established National Flag Day.
On June 14, 1954, Dwight Eisenhower signed Joint Resolution (Public Law 396) adding the phrase “One Nation Under God” to the Pledge of Allegiance to the Flag.
The U.S. Army also celebrates the Army birthday on this date. Congress adopted "the American continental army" on June 14, 1775.