“The Star-Spangled Banner” can be heard at sporting events across the US. Some people appreciate the chance to pause for patriotism. But others use the singing of the national anthem as a time for protest. High-profile examples have included NFL players kneeling during the anthem to protest social injustice. There has been strong support for and against protests. But just how – and when – was “The Star-Spangled Banner” introduced to sporting events in the first place?