The US national anthem or The Star Spangled Banner was inspired by the events at the Battle of Baltimore, one of the key battles in the War of 1812.
The story goes that when Francis Scott Key saw the American flag flying above Fort McHenry admidst the cannon fire, he was inspired to write the poem "Defence of Fort McHenry", which was later put to music- at the recommendation of Key to be sung as a song to the popular British tune, "To Anacreon in Heaven"- to become the star spangled banner as we know it today.
The song became the national anthem of the USA on 3rd March 1931 when the president at the time, Herbert Hoover, passed an act to make it official. Before this time, the US did not have a national anthem.
Hear is a very modern rendition sung by America's first lady- no, the other one- Beyonce:
