The Star-Spangled Banner flag that inspired the U.S. national anthem had 15 stars.
The enormous flag flew over Fort McHenry during the Battle of Baltimore in September 1814, part of the War of 1812. Francis Scott Key saw it after spending the night watching the British bombardment and was inspired to write the poem later known as “The Star-Spangled Banner.”
The flag also had 15 stripes. Congress had temporarily increased both the stars and stripes from 13 to 15 after Vermont and Kentucky joined the Union. That design was used from 1795 until 1818.
Mary Pickersgill and assistants made the flag in Baltimore. The surviving flag is preserved by the Smithsonian’s National Museum of American History, where conservation work has helped protect its unusually large and fragile fabric.