Europeans, in the form of French and Scots-Irish traders from Detroit and elsewhere, did not return until the following spring, with the understanding that they would trade more fairly with the Native Americans. The British abandoned the vulnerable site on the mainland during the American Revolutionary War; from 1779 to 1781, the troops moved the fort, including its buildings, to Mackinac Island, where they established Fort Mackinac. What the British did not take with them, they burned; that way they could prevent the American rebels from using Michilimackinac as a base.