Promoted to lieutenant general in North America, he began his service in 1776 under General Sir Henry Clinton with the failed siege of Charleston. He and Clinton then sailed for New York City, where they participated in General William Howe's campaign for New York City. Cornwallis was often given a leading role during this campaign; his division was in the lead at the Battle of Long Island, and he chased the retreating George Washington across New Jersey after the city fell. Howe recognized the successful close of the campaign "much to the honor of his lordship and the officers and soldiers under his command."