After the outbreak of the War of Independence in 1775, Craig took part in the Battle of Bunker Hill, where he was badly wounded, but refused to leave his regiment, and participated in the defence of Quebec in 1776, where he met the American invaders at Trois-Rivières while commanding the advance guard that forced them back beyond the border. During 1777 he was wounded twice, once seriously, during engagements at Fort Ticonderoga, Hubbardton, and Freeman's Farm. Major-General John Burgoyne, who expressed high regard for Craig as an officer, recommended him for the rank of a major in the 82nd Regiment of Foot (1777) in recognition of his service. From 1778 to 1781 Craig served with the 82nd Regiment in Nova Scotia, at Penobscot, and later in North Carolina. Due to constant involvement in operations during the war, Craig usually led light infantry troops. His rapid promotion suggests that Craig possessed an unusual degree of initiative and resourcefulness.