It's not like that's our national anthem, and besides, that tune existed long before our country did, and t is in good musical tradition to borrow old tunes for new uses. The author of the tune is unknown, and it may originate in plainchant, but a 1619 attribution to John Bull is sometimes made. So no one is even sure who write the tune!
The Star-Spangled Banner is set to the tune of a popular British song written by John Stafford Smith for the Anacreontic Society, a men's social club in London.
So despite the xenophobics/chauvinists - Fortress America has borrowed freely and interacted frequently!