One iconic emblem of the battle was the flag designed by Colonel Moultrie . Commissioned by the colonial government , he designed a blue flag with a white crescent in the top left corner , which was flown at the fort during the battle . Despite being shot down during the siege , it was seen as a symbol of this successful defense ( and famously raised during victory ) . It came to be known as the Moultrie flag or Liberty Flag . When Charleston ( lost to the British in the 1780 siege ) was reclaimed by American forces at the end of the war , the flag was returned to the city by General Nathanael Greene .