Fifteen stars appeared on the U.S. flag design adopted in 1795.
The Flag Act of 1794 added stars and stripes for Vermont and Kentucky, which had joined the Union after the original thirteen states. The resulting flag therefore displayed fifteen stars and fifteen stripes. This design was used from May 1, 1795, until July 3, 1818.
The fifteen-star flag is especially associated with the War of 1812. A large fifteen-star, fifteen-stripe flag flew over Fort McHenry during the British attack on Baltimore in September 1814. Its survival inspired Francis Scott Key to write the poem later known as “The Star-Spangled Banner.”
Congress eventually ended the practice of adding a stripe for each new state. The Flag Act of 1818 restored the number of stripes to thirteen and established the practice of adding a star for each new state. The current flag has fifty stars and thirteen stripes.