<P> The Star - Spangled Banner, or the Great Garrison Flag, was the garrison flag that flew over Fort McHenry in Baltimore Harbor during the naval portion of the Battle of Baltimore during the War of 1812 . Seeing the flag during the battle inspired Francis Scott Key to write the poem "Defence of Fort M'Henry", which, retitled with the flag's name from the closing lines of the first stanza and set to the tune of "To Anacreon in Heaven" by John Stafford Smith, later became the national anthem of the United States . </P> <P> 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 expressed desire for a very large flag to fly over the fort, General John S. Stricker and Commodore Joshua Barney placed an order with a prominent Baltimorean flagmaker 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 . </P>

The battle that inspired the star spangled banner