Lord Cornwallis had been completely roused from his dream of security by the appearance, on the 28th of August, of the fleet of Count de Grasse within the capes of the Delaware. Three French ships-of-the-line and a frigate soon anchored at the mouth of York River. The boats of the fleet were immediately busy conveying three thousand three hundred land forces, under the Marquis de St. Simon, up James River to form the preconcerted junction with those under Lafayette. Awakened to his danger, Cornwallis, as Washington had foreseen, meditated a retreat to the Carolinas. It was too late. York River was blocked up by French ships; James River was filled with armed vessels covering the transportation of the troops. His lordship reconnoitred Williamsburg; it was too strong to be forced, and Wayne had crossed James River to join his troops to those under the marquis. Seeing his retreat cut off in every direction, Cornwallis proceeded to strengthen his works; sending off repeated expresses to apprise Sir Henry Clinton of his perilous situation.
The Count de Grasse had been but a few days anchored within the Chesapeake, and fifteen hundred of his seamen were absent, conveying the troops up James River, when Admiral Graves, who then commanded the British naval force on the American coast, appeared with twenty sail off the capes of Virginia. De Grasse, anxious to protect the squadron of the Count de Barras, which was expected from Rhode Island, and which it was the object of Graves to intercept, immediately slipped his cables and put to sea with twenty-four ships, leaving the rest to blockade York and James Rivers.
Admiral Graves, immediately prepared for action, although he had five ships less than De Grasse. The latter, however, was not disposed to accept the challenge, his force being weakened by the absence of so many of his seamen, employed in transporting troops. His plan was to occupy the enemy by partial actions and skilful manoeuvres, so as to retain his possession of the Chesapeake, and cover the arrival of De Barras.
The vans of the two fleets, and some ships of the centre, engaged about four o'clock in the afternoon of the 7th of September. The conflict soon became animated. Several ships were damaged, and many men killed and wounded on both sides. De Grasse, who had the advantage of the wind, drew off after sunset; satisfied with the damage done and sustained, and not disposed for a general action. For four days the fleets remained in sight of each other, repairing damages and manoeuvring; but the French having still the advantage of the wind, maintained their prudent policy of avoiding a general engagement. At length De Grasse, learning that De Barras was arrived within the capes, formed a junction with him, and returned with him to his former anchoring ground, with two English frigates which he had captured. Admiral Graves, disappointed in his hope of interrupting De Barras, and finding the Chesapeake guarded by a superior force with which he could not prudently contend, left the coast and bore away for New York. Under convoy of the squadron of De Barras came a fleet of transports, conveying land forces under M. de Choisy, with siege artillery and military stores.
From Williamsburg, Washington sent forward Count Fersen, one of the aides-de-camp of De Rochambeau, to hurry on the French troops with all possible despatch. He wrote to the same purport to General Lincoln: "Every day we now lose," said he, "is comparatively an age; as soon as it is in our power with safety, we ought to take our position near the enemy. Hurry on, then, my dear sir, with your troops, on the wings of speed."
It was with great satisfaction Washington learned that Admiral de Barras had anticipated his wishes, in sending transports and prize vessels up the bay to assist in bringing on the French troops. In the meantime, he with Count de Rochambeau was desirous of having an interview with the admiral on board of his ship, provided he could send some fast-sailing cutter to receive them. A small ship, the Queen Charlotte, was furnished by the admiral for the purpose. It had been captured on its voyage from Charleston to New York, having Lord Rawdon on board, and had been commodiously fitted up for his lordship's reception.
On board of this vessel Washington and De Rochambeau, with the Chevalier de Chastellux and Generals Knox and Duportail, embarked on the 18th, and proceeding down James River, came the next morning in sight of the French fleet riding at anchor in Lynn Haven Bay, just under the point of Cape Henry. About noon they got alongside of the admiral's ship, the Ville de Paris, and were received on board with great ceremony, and naval and military parade. Admiral de Grasse was a tall, fine-looking man, plain in his address and prompt in the discharge of business. A plan of co-operation was soon arranged, to be carried into effect on the arrival of the American and French armies from the North, which were actually on their way down the Chesapeake from the Head of Elk. Business being despatched, dinner was served, after which they were conducted throughout the ship, and received the officers of the fleet, almost all of whom came on board.
By the 25th the American and French troops were mostly arrived and encamped near Williamsburg, and preparations were made for the decisive blow.
Yorktown, as has already been noted, is situated on the south side of York River, immediately opposite Gloucester Point. Cornwallis had fortified the town by seven redoubts and six batteries on the land side, connected by intrenchments; and there was a line of batteries along the river. The town was flanked on each side by deep ravines and creeks emptying into York River; their heads, in front of the town, being not more than half a mile apart. The enemy had availed themselves of these natural defences, in the arrangement of extensive outworks, with redoubts strengthened by abatis; field-works mounted with cannon, and trees cut down and left with the branches pointed outward. Gloucester Point had likewise been fortified. Its batteries, with those of Yorktown, commanded the intervening river. Ships of war were likewise stationed on it, protected by the guns of the forts, and the channel was obstructed by sunken vessels. The defence of Gloucester Point was confided to Lieutenant-colonel Dundas, with six or seven hundred men.
That evening Cornwallis received despatches from Sir Henry Clinton, informing him of the arrival of Admiral Digby, and that a fleet of twenty-three ships-of-the-line, with about five thousand troops, would sail to his assistance probably on the 5th of October. Cornwallis immediately wrote in reply: "I have ventured these last two days to look General Washington's whole force in the face in the position on the outside of my works, and have the pleasure to assure your Excellency that there is but one wish throughout the army, which is that the enemy would advance.... I shall retire this night within the works, and have no doubt, if relief arrives in any reasonable time, York and Gloucester will be both in the possession of his Majesty's troops." That night his lordship accordingly abandoned his outworks, and drew his troops within the town. The outworks thus abandoned were seized upon the next morning by detachments of American light infantry and French troops, and served to cover the troops employed in throwing up breastworks.