About midsummer, the joyous news reached Washington that a powerful French fleet, with an army on board, was about to sail for America. With this reinforcement, Washington had it in his power to deliver a blow which would break the strength of the enemy, and hasten the close of the war. Clinton held New York, and Cornwallis was fortifying himself in Yorktown. The French fleet sailed for the Chesapeake, and Washington decided in consequence that his attack should be made on Lord Cornwallis. With all possible secrecy and speed the American troops were moved southwards to Virginia. They were joined by the French, and they stood before Yorktown a force twelve thousand strong. Cornwallis had not expected them, and he called on Clinton to aid him. But it was too late. He was already in a grasp from which there was no escaping. Throughout the war, the weakness of his force often obliged Washington to adopt a cautious and defensive policy, which grievously disappointed the expectations of his impatient countrymen. It is not therefore to be imagined that his leadership was wanting in vigour. Within his calm and well-balanced mind there lurked a fiery energy, ready to burst forth when occasion required. The siege of Yorktown was pushed on with extraordinary vehemence. The English, as their wont is, made a stout defence, and strove by desperate sallies to drive the assailants from their works. But in a few days the defences of Yorktown lay in utter ruin, beaten to the ground by the powerful artillery of the Americans. The English guns were silenced; the English shipping was fired by red-hot shot from the French batteries. Ammunition began to grow scarce. The place could not be held much longer, and Clinton still delayed his coming. Lord Cornwallis must either force his way out and escape to the North, or surrender. One night he began to embark his men in order to cross the York river and set out on his desperate march to New York; but a violent storm arose and scattered his boats. The men who had embarked got back with difficulty, under fire from the American batteries. All hope was now at an end. In about a fortnight from the opening of the siege, the British army, eight thousand strong, laid down its arms. The joy of America over this great crowning success knew no bounds. One highly emotional patriot was said to have expired from mere excess of rapture. Some others lost their reason. In the army, all who were under arrest were at once set at liberty. A day of solemn thanksgiving was proclaimed and devoutly observed throughout the rejoicing States.