The Fort McHenry flag, which flew over the fort for the time of its bombardment in 1814

https://remote-wiki.win/index.php/Famous_Civil_War_Battles_Fought_Under_the_Union_Flag_American_Flag

The Fort McHenry flag, which flew over the castle for the duration of its bombardment in 1814, changed into an logo of resilience and patriotism that influenced Key’s anthem.