Flag Day celebrates America's first symbol of independence from the British. At the beginning of the American Revolution, each regiment fought under their own flag. To give its army a single banner to fight under, the Second Continental Congress passed the Flag Act of 1777. Flag Day is celebrated on June 14 because of the American flag's historic creation on that day thirteen stripes, alternate red and white; that the union be thirteen stars, white in a blue field representing a new constellation, Flag Act of 1777. The first official Flag Day was established by President Woodrow Wilson in 1916.