“Our Flag Was Still There” The Origin of the Star-Spangled Banner Posted September 14, 2012 The bombardment of Fort McHenry took place on September 13th and 14th, 1814. Francis Scott Key, held captive aboard a Royal Navy warship, watched as the British attacked the fort and other defenses of Baltimore. This flag at Fort Mackinac, though smaller than the one seen by Francis Scott Key the morning of September 14, bears the 15 stars and stripes. By the dawn’s early light of September 14, he saw that the American flag remained flying above the fort. The large garrison flag that Key saw flying that morning 198 years ago measured 30 by 42 feet and bore 15 stars and 15 stripes (one for each state). Inspired by the sight of the flag, that morning Key wrote a poem about the battle called “The Defense of Fort McHenry.” Later set to music, the poem became “The Star-Spangled Banner,” which officially became the National Anthem of the United States in 1931.