#OnThisDay in 1814 Francis Scott Key was inspired to write the poem "Defense of Fort McHenry" after witnessing the British attack on the titular fort while being held in Baltimore Harbor under guard of the British Navy. Key went on to set his poem to the tune of "Anacreon in Heaven" and the resulting song, The Star Spangled Banner, soon became the de facto national anthem of the new USA. It was made official in 1931 by Congress. #HistoryGetsLIT