American Military History, Volume 1 by Richard W. Stewart

While the Continental Army was undergoing its ordeal and transformation at Valley Forge, Howe dallied in Philadelphia, forfeiting whatever remaining chance he had to win a decisive victory before the effects of the French alliance were felt. He had had his fill of the American war; and the king accepted his resignation from command, appointing General Clinton as his successor. As Washington prepared to sally forth from Valley Forge, the British Army and the Philadelphia Tories said goodbye to Howe in a series of lavish parties. However, Clinton already had orders to evacuate the American capital. With the French in the war, the strategic situation had changed dramatically. England now had to ensure the safety of the long ocean supply line to America, as well as its valuable commercial possessions in other parts of the world, in particular the rich sugar plantations of the Caribbean. Clinton's orders were to detach 5,000 men to the West Indies and 3,000 to Florida and to return the rest of his army to New York by sea. He was then to give thought to recovering the southern states, where once again ever-hopeful refugees insisted the majority of the population would rally to the royal standard.

With the French in the war, the strategic situation had changed dramatically.