The History of the Bunker Hill Flag: On the night of June 16-17, 1775, the Americans fortified Breed's and Bunker Hills overlooking Boston Harbor. Although they had not officially declared their independence, a fight was underway. When the British advanced up the slope the next day they saw an early New England flag, possibly a red or blue banner later known as the Bunker Hill flag. Many early Colonial flags had been made by altering the English flag and most still contained a reference to the mother country. This was an example that the Colonists still saw themselves as British subjects but were declaring their right to be free from violation of their liberties.