against the British, leading to ultimately unsuccessful attempts to dislodge the British from Newport, Rhode Island, and Savannah, Georgia. His attention was also drawn to the frontier war, which prompted the 1779 Continental Army expedition of John Sullivan into upstate New York. When General Clinton sent the turncoat General Benedict Arnold to raid in Virginia, Washington began to detach elements of his army to face the growing threat there. The arrival of Lord Cornwallis in Virginia after campaigning in the south presented Washington with an opportunity to strike a decisive blow. Washington's army and the French army moved south to face Cornwallis, and a cooperative French navy under Admiral de Grasse successfully disrupted British attempts to control of the Chesapeake Bay, completing the entrapment of Cornwallis, who surrendered after the Siege of Yorktown in October 1781. Although Yorktown marked the end of significant hostilities in North America, the British still occupied New York and other cities, so Washington had to maintain the army in the face of a bankrupt Congress and troops that were at times mutinous over conditions and pay. The army was formally disbanded after peace in 1783, and Washington resigned his commission as commander-in-chief on December 23, 1783. Military experience Born into a well-to-do Virginia family near Fredericksburg in , Washington was schooled locally until the age of 15. The early death of his father when he was 11 eliminated the possibility of schooling in England, and his mother rejected attempts to place him in the Royal Navy. Thanks to the connection by marriage of his half-brother Lawrence to the wealthy Fairfax family, Washington was appointed surveyor of Culpeper County in 1749; he was just 17 years old. Washington's brother had purchased an interest in the Ohio Company, a land acquisition and settlement company whose objective was the settlement of Virginia's frontier areas, including the Ohio Country, territory north and west of the Ohio River. Its investors also included Virginia's Royal Governor, Robert Dinwiddie, who appointed Washington a major in the provincial militia in February 1753. Washington played a key role in the outbreak of the French and Indian War, and then led the defense of Virginia between 1755 and 1758 as colonel of the Virginia Regiment. Although Washington never received a commission in the British Army, he gained valuable military, political, and leadership skills, and received significant public exposure in the colonies and abroad. He closely