The strategy of the British in North America was to deploy a combination of operations aimed at capturing major cities and a blockade of the coast. The British took Long Island in August 1776 and captured New York City in September 1776 in combined operations involving the army and the navy during the New York and New Jersey campaign. He represented the Crown at the Staten Island Peace Conference held on 11 September 1776. In 1777 Howe provided support to his brother's operation to capture Philadelphia, ferrying General Howe's army to a landing point from which they successfully marched and took the city.

Howe spent much of the remainder of the year concentrating on capturing Forts Mifflin and Mercer which controlled entry to the Delaware River without which ships could not reach Philadelphia. News of the capture of a separate British army under General John Burgoyne threw British plans into disarray. Howe spent the winter in Newport, Rhode Island.

Declining to serve afterwards, Howe cited distrust of Lord North and a lack of support during his command in America. He was further embittered by the replacement of himself and his brother as peace commissioners, as well as by attacks in the press against him by ministerial writers including the prominent American Loyalist Joseph Galloway. An inquiry in Parliament demanded by the Howe brothers to justify their conduct in America was held during 1779 but ended inconclusively. Howe spent much of the next three years with the opposition attacking the government's alleged mismanagement of the war at sea.