Mawhood was left in command of a force at Princeton, New Jersey by Lord Cornwallis in January 1777 while Cornwallis chased after George Washington 's army after the Battle of Trenton. Mawhood continued to serve in North America, seeing further action during the 1777–1778 Philadelphia campaignleading a mixed force of regulars, loyalists and rangers in a series of raids through New Jersey. After Cornwallis's attack in Trenton was stopped, Washington sneaked his army around that of Cornwallis and attacked the Princeton garrison. Mawhood acquitted himself well in the battle, and was mentioned in dispatches. Later, Mawhood received a message from the King, noting his bravery. He transferred to the 17th Foot on 26 October 1775 and served with this regiment during General Howe's early campaigns of the American War of Independence. With the advent of war with France and Howe's resignation as commander in chief, Mawhood played no further part in the war in North America and returned to England. Mawhood's colonelcy was transferred to one of the newly raised volunteer regiments which had been quickly raised in response to the advent of war with France. In 1778 the Royal Manchester Volunteers (72nd Foot) were raised by public subscription by the City of Manchester and deployed to the garrison of Gibraltar. In 1780 Mawhood was chosen to lead reinforcements to the besieged garrison, arriving with the fleet of Admiral George Rodney which broke through the French blockade in January. Mawhood died during the siege on 29 August 1780 after suffering from a gall-stone.