On this day in 1777, during the American Revolution, the Continental Congress adopts a resolution stating that "the flag of the United States be thirteen alternate stripes red and white" and that "the Union be thirteen stars, white in a blue field, representing a new Constellation."

With the entrance of new states into the United States after independence, new stripes and stars were added to represent new additions to the Union. In 1818, however, Congress enacted a law stipulating that the 13 original stripes be restored and that only stars be added to represent new states.

On June 14, 1877, the first Flag Day observance was held on the 100th anniversary of the adoption of the American flag. As instructed by Congress, the U.S. flag was flown from all public buildings across the country. In 1949 Congress officially designated June 14 as Flag Day, a national day of observance.