Carleton served as the fourth and last British commander-in-chief in North America during the American War for Independence. During the initial stages of the war, Carleton led the defenses of Canada in repelling the American 1775 invasion. In this capacity, Carleton received praise for his defense of Quebec City and scorn for not aggressively pursuing the retreating Americans and recapturing Ft. Ticonderoga in upper New York State.
After the Canadian defense, Frederick Haldemand replaced Carleton as Canadian governor. However, Carleton returned to New York in 1782 to replace Henry Clinton as North American commander-in-chief. In the later stages of the war, Carleton had orders to surrender if they Americans launched a credible threat to the British post in New York City. However, no threat materialized and he oversaw the evacuation of the British Army and its dependents. Carleton’s most controversial decision was to protect former slaves and transport them to other parts of the British empire.