The Battle of Sullivan's Island was on June 28 ,1776 . It is mostly overlooked by history because the signing of the Declaration of Independence happened a few days later .

But without a colonial victory in Charleston Harbor that day ;there could've been a completely different outcome to the Revolution.

Battle of Sullivan's Island - History (historyonthenet.com) (https://www.historyonthenet.com/battle-sullivans-island)