The first official United States flag had thirteen stripes under the 1777 Flag Resolution.
On June 14, 1777, the Continental Congress resolved that the flag should have thirteen alternating red and white stripes and thirteen white stars on a blue field. The stripes represented the thirteen United States formed from the former colonies.
The resolution did not specify the stars’ exact arrangement, so early flags varied. It also did not state the precise orientation or dimensions of the flag. The familiar modern arrangement developed later as new states joined the Union.
Congress temporarily increased the number of stripes to fifteen in 1795 when Vermont and Kentucky joined. In 1818, it returned the stripe count to thirteen while allowing additional stars for new states.