Is it only me who hears similarities in the airs used for the two patriotic songs?
According to wiki, the Star-Spangled Banner tune was based on John Stafford Smith's air for "The Anacreontic Song ", the official song of the Anacreontic Society ( an 18th-century gentlemen's club of amateur musicians named after the 6 century BC Greek court poet Anacreon).

The Anacreontic Song's tune was later used by writers as a setting for patriotic lyrics. The song became popular in Britain and also America following the establishment of several Anacreontic Societies there.