The regiment returned to America arriving at Boston in April 1775 for service in the American Revolutionary War. It suffered tremendous casualties at the Battle of Bunker Hill in June 1775: of the Light Infantry, all officers and non-commissioned officers were killed or wounded and of the Grenadier Company only five soldiers were alive and unscathed. The regiment suffered the hardships of the siege of Boston in spring 1776 before sailing to New York and taking part in the Battle of Long Island in July 1776 and the Battle of Harlem Heights in September 1776. The commanding officer of the regiment, Lieutenant Colonel Robert Carr, was killed at the Battle of White Plains in October 1776 and, under fresh command, the regiment fought again at the Battle of Fort Washington in November 1776. It saw action in the Philadelphia campaign during much of 1777 and then sailed for the West Indies in July 1778. It took part in the Capture of St. Lucia in December 1778 and then returned to England in September 1785.