3x5 Cotton, Star Spangled Banner, Period Authentic, Made in The USA with brass grommets. Annin 318900

The Star-Spangled Banner, or the Great Garrison Flag, was the garrison flag that flew over Fort McHenry in Baltimore Harbor during the Battle of Baltimore during the War of 1812. The original flag is on exhibit at the National Museum of American History, Smithsonian Institution. Seeing the flag flying over Fort McHenry on the morning of September 14, 1814, after the battle ended, Francis Scott Key was inspired to write the poem "Defense of Fort McHenry". These words were written by Key and set to the tune of "To Anacreon in Heaven", a popular song at the time, by John Stafford Smith. In 1931, the song became the national anthem of the United States. With fifteen stripes, the Star-Spangled Banner remains the only official American flag to bear more than thirteen stripes.

In Baltimore's preparation for an expected attack on the city, Fort McHenry was made ready to defend the city's harbor. When Major George Armistead, the fort's commander, expressed the desire for a very large flag to fly over the fort, General John S. Stricker and Commodore Joshua Barney placed an order for two oversized American flags. The larger of the two flags would be the Great Garrison Flag, the largest battle flag ever flown at the time. The smaller of the two flags would be the Storm Flag, to be more durable and less prone to fouling in inclement weather.

The flag was sewn by prominent Baltimorean flagmaker Mary Young Pickersgill under a government commission in 1813 at a cost of $405.90 (equivalent to $6,613 in 2024). Armistead specified "a flag so large that the British would have no difficulty seeing it from a distance". The flag original flag measured 30 by 42 feet, the largest US flag ever made at the time, and weighed about 50 pounds. Each of the fifteen stripes is 2 feet wide, and each of the stars measure nearly 2 feet in diameter.