 After the failure in South Carolina , Clinton and Cornwallis transported their troops north to serve under William Howe in the campaign for New York City . In the Battle of Long Island , Cornwallis led the reserve division that took part in the successful flanking of the American position on Gowanus Heights . Cornwallis 's role in the following weeks was minor ; his command was not directly involved in the battles that drove George Washington across the Hudson River and into New Jersey . At the fall of Fort Washington , Cornwallis 's troops sealed one of the last escape routes . General Howe then gave Cornwallis his first chance at an independent command , assigning him to capture Fort Lee across the river from Fort Washington . The Americans occupying that fortification were led by Nathanael Greene , who would later face Cornwallis in the south , and only barely made their escape . Cornwallis 's prizes in the bloodless seizure of the fort included tents , guns , and other military supplies . Washington ended up withdrawing all the way across the Delaware River into Pennsylvania , with Cornwallis in pursuit until his force reached New Brunswick . His troops were exhausted from the chase , and his orders from Howe were to go no further . Cornwallis , who was criticized for disobeying or disregarding Clinton 's orders in later campaigns , observed that he would have disobeyed Howe 's orders if he believed further pursuit would have gained material advantage for the British . Howe joined him on December 6 , and led the pursuit to the Delaware with Cornwallis in the van . In his orders of December 14 , Howe recognized the successful close of the campaign " much to the honor of his lordship and the officers and soldiers under his command . " 
