Howe served in the colonial militia during the French and Indian War and commanded Fort Johnston at the mouth of the Cape Fear River. He also served as a colonel of Royal Governor William Tryon's artillery during the War of the Regulation. Howe suffered greatly when Tryon, a personal friend, became Governor of New York, and he staunchly opposed Tryon's successor. He became active in organizing efforts within North Carolina and among the American colonies between 1773 and 1775 and was an active member of the North Carolina Provincial Congress. At the outset of the Revolutionary War, Howe was promoted to brigadier general and was heavily involved in actions in the Southern Department, commanding the Continental Army and Patriot militia forces in defeat in the First Battle of Savannah.