end of the day. That midnight, the newly installed Clinton continued his retreat to New York. A French naval force under Admiral Charles Henri Hector d'Estaing was sent to assist Washington; deciding New York was too formidable a target, in August they launched a combined attack on Newport, with General John Sullivan commanding land forces. The resulting Battle of Rhode Island was indecisive; badly damaged by a storm, the French withdrew to avoid putting their ships at risk. Further activity was limited to British raids on Chestnut Neck and Little Egg Harbor in October. In July 1779, the Americans captured British positions at Stony Point and Paulus Hook. Clinton unsuccessfully tried to tempt Washington into a decisive engagement by sending General William Tryon to raid Connecticut. In July, a large American naval operation, the Penobscot Expedition, attempted to retake Maine, then part of Massachusetts, but was defeated. Persistent Iroquois raids along the border with Quebec led to the punitive Sullivan Expedition in April 1779, destroying many settlements but failing to stop them. During the winter of 1779–1780, the Continental Army suffered greater hardships than at Valley Forge. Morale was poor, public support fell away in the long war, the Continental dollar was virtually worthless, the army was plagued with supply problems, desertion was common, and mutinies occurred in the Pennsylvania Line and New Jersey Line regiments over the conditions in early 1780. In June 1780, Clinton sent 6,000 men under Wilhelm von Knyphausen to retake New Jersey, but they were halted by local militia at the Battle of Connecticut Farms; although the Americans withdrew, Knyphausen felt he was not strong enough to engage Washington's main force and retreated. A second attempt two weeks later ended in a British defeat at the Battle of Springfield, effectively ending their ambitions in New Jersey. In July, Washington appointed Benedict Arnold commander of West Point; his attempt to betray the fort to the British failed due to incompetent planning, and the plot was revealed when his British contact John André was captured and later executed. Arnold escaped to New York and switched sides, an action justified in a pamphlet addressed "To the Inhabitants of America"; the Patriots condemned his betrayal, while he found himself almost as unpopular with the British. War in the South The "Southern Strategy" was developed by Lord Germain, based on input from London-based Loyalists like Joseph Galloway. They argued it