In Parliament, where he was member for Westminster from 1763 to 1776, he had opposed the policy that led to the
American War of Independence. However, he was sent to Boston in 1774 with the local rank of
brigadier general, colonel of the
5th Regiment of Foot (later called the Northumberland Fusiliers). His views on the military discipline were ahead of their time. "He detested
corporal punishments. At a time when other commanders were resorting to floggings and firing squads on Boston Common, he led his regiment by precept and example." When a final colonial force tried to block British progress at Prospect Hill, "Percy advanced his cannon to the front of his column, and cleared the hill with a few well-placed rounds. It was the last of his ammunition for the artillery. Percy's attitude towards New Englanders turned from contempt to grudging respect. He wrote: During the whole affair, the rebels attacked us in a very scattered, irregular manner, but with perseverance and resolution, nor did they ever dare to form into a regular body. Indeed they knew too well what was proper, to do so. Whoever looks upon them as an irregular mob, will find himself very much mistaken. They have men amongst them who know very well what they are about, having been employed as rangers against the Indians and Canadians, and this country being very much covered with wood, and hilly, is very advantageous for their method of fighting. He was absent from the main action during the
Battle of Bunker Hill, tasked with firing artillery into
Roxbury. The following year, Percy commanded a division during the
Battle of Long Island and led the storming of
Fort Washington. By 1777, he had achieved the rank of
lieutenant general, but grew so disgusted with the conduct of the war by General Howe that he resigned his command and left America in 1777 in part after a dispute over a quantity of hay. More substantively, while in command of a detached British force garrisoning Rhode Island he fell into disagreement with General Howe over the feasibility of advancing into the hostile New England hinterland. ==Second marriage==