That summer, he led an expedition against Fort Ticonderoga. Abercrombie was a genius at organization, but vacillated in his leadership to the point where his troops called him Mrs. Nanny Cromby. He managed the remarkable feat of assembling 15,000 troops and moving them and their supplies through the wilderness. Then, on July 8, 2,000 of them were killed, which proved that 15,000 men cannot take a stone fort manned by 3,000 with artillery through frontal assault with bayonets. Eventually his force panicked and fled, and he retreated to his fortified camp south of Lake George. This disaster caused his replacement by General Jeffrey Amherst and his recall to England in 1759. On his return to England, he sat as a member of parliament, and supported the coercive policy toward the American colonies.
James Abercrombie Junior
General Abercrombie's son was Lieutenant Colonel James Abercrombie (?-June 24, 1775). He had served as a Captain in the 42nd Foot before being made aide-de-camp to General Amherst in 1759, and was promoted to the grade of lieutenant colonel in 1770. At the Battle of Bunker Hill he led the grenadier battalion in their charge of the redoubt on the left wing. He was shot during that charge, and carried from the field. He was taken to hospital facilities in Boston where died from his wound a week later.