The flag that inspired Francis Scott Key to write “The Star-Spangled Banner” had 15 stars.
Key saw the large flag flying over Fort McHenry after the British bombardment during the Battle of Baltimore on September 14, 1814. The flag was made for Fort McHenry by Mary Young Pickersgill and displayed 15 white stars and 15 stripes, representing the 15 states then in the Union.
The national flag had gained two stars and two stripes after Vermont and Kentucky joined the United States. Congress later changed the design so that new states added stars but not stripes. The flag that flew over Fort McHenry became a national relic, while Key’s poem, originally titled “Defence of Fort M'Henry,” was set to the tune of a British song and became the national anthem in 1931.