Before his first tour of duty in North America, Christopher married Anne Howard, whose sister Maria was the wife of Guy Carleton.
While in North America, Christopher Carleton met Sir William Johnson and lived among the Mohawk Indians, learning their language and partaking in their customs.
In 1777, Christopher purchased a major's commission in the 29th Regiment of Foot, in which his uncle, Thomas Carleton, was a lieutenant colonel.
In the autumn of 1778, Major Christopher Carleton led a raid along the shores of Lake Champlain burning the towns along Otter Creek in Vermont and taking the local militia men prisoner.
The years spent on the cold northern frontiers of North America took their toll on now Lieutenant-Colonel Christopher Carleton's health and he died on June 14, 1787, at Quebec City.