See main articles: Saratoga Campaign and Fort Stanwix
In 1777, while he was the Lt. Colonel of the 34th foot, he was chosen to lead the western offensive that formed one leg of the Saratoga Campaign. John Burgoyne made him brevet Brigadier General for this mission so that he would outrank the militia officers involved. He move his force in good order to Fort Stanwix, but finding it strongly defended, set a siege in motion. He beat back the American militia attempt to break the siege by ambushing Nicholas Herkimer's force in the Battle of Oriskany. When rumors of a relief force under Benedict Arnold reached him he was forced to withdraw back to Canada.