January 13, 1794, President George Washington signed the law adding two stars and two stripes to the U.S. flag, after Vermont and Kentucky joined the union.
This was the only U.S. flag ever officially to have more than 13 stripes.
The “Star-spangled Banner” that flew over Ft. McHenry, near Baltimore, which inspired Francis Scott Key to write the poem which was put to music to form our national anthem, had 15 stripes. President James Monroe signed a law in 1818 that specified 13 stripes, with a new star to be added on July 4 of any year after a new state was added, a practice which has held through our current 50-star, 13-stripe flag.
Tennessee was the 16th state. I have been unable to clarify what happened with the number of stripes between Tennessee’s admission to the union on June 1, 1796, and the law passed in the Monroe administration in 1818. Does anyone know? Got links?
More (added after August 2013):
- A Smithsonian Magazine history of the U.S. flag, with notes to each official change