The French troops, under Rochambeau, marched from Newport and Boston toward the Hudson. Both in quarters and on the route their behavior was exemplary, and gained the respect and good will of the inhabitants. Toward the end of June (1781) Washington put his army in motion, and, learning that a royal detachment had passed into the Jerseys, he formed a plan to surprise the British posts on the north end of York Island, but it did not succeed, and General Lincoln, who commanded the Americans, being attacked by a strong British party, a sharp conflict ensued. Washington marched with his main body to support his detachment, but on his advance the British retired into their works at Kingsbridge. Rochambeau, then on his march to join Washington, detached the Duke de Lauzun with a body of men to support the attack, who advanced with his troops within supporting distance, but the British had retreated before they could be brought into action.
Having failed in his design of surprising the British posts Washington withdrew to Valentine's Hill, and afterward to Dobb's Ferry. While encamped there, on the 6th of July (1781), the van of the long-expected French reinforcements under Rochambeau was seen winding down the neighboring heights. The arrival of these friendly strangers elevated the minds of the Americans, who received them with sincere congratulations. Washington labored, by personal attentions, to conciliate the good will of his allies, and used all the means in his power to prevent those mutual jealousies and irritations which frequently prevail between troops of different nations serving in the same army. An attack on New York was still meditated, and every exertion made to prepare for its execution, but with the determination, if it should prove impracticable, vigorously to prosecute some more attainable object. {1}
On the evening of the 21st of July (1781), the greater part of the American, and part of the French troops, left their encampment, and marching rapidly during the night, appeared in order of battle before the British works at Kingsbridge, at 4 next morning. Washington and Rochambeau, with the general officers and engineers, viewed the British lines in their whole extent from right to left, and the same was again done next morning. But, on the afternoon of the 23d they returned to their former encampment without having made any attempt on the British works.
At that time the new levies arrived slowly in the American camp, and many of those who were sent were mere boys utterly unfit for active service. The several States discovered much backwardness in complying with the requisitions of Congress, so that there was reason to apprehend that the number of troops necessary for besieging New York could not be procured. This made Washington turn his thoughts more seriously to the southward than he had hitherto done, but all his movements confirmed Clinton in the belief that an attack on New York was in contemplation. As the British Commander-in-Chief, however, at that time received about 3,000 troops from Europe, he thought himself able to defend his post without withdrawing any part of the force from Virginia. Therefore he countermanded the requisition which he had before sent to Cornwallis for part of the troops under his command. The troops were embarked before the arrival of the counter order, and of their embarkation Lafayette sent notice to Washington. On the reception of new instructions, however, as formerly mentioned they were relanded and remained in Virginia.
No great operation could be undertaken against the British armies so long as their navy had undisputed command of the coast and of the great navigable rivers. Washington, as we have seen, had already, through Colonel Laurens, made an earnest application to the court of France for such a fleet as might be capable of keeping in check the British navy in those seas and of affording effectual assistance to the land forces. That application was not unsuccessful, and towards the middle of the month of August the agreeable information was received of the approach of a powerful French fleet to the American coast.
Early in March (1781) the Count de Grasse had sailed from Brest with twenty-five ships-of-the-line, five of which were destined for the East, and twenty for the West Indies. After an indecisive encounter in the Straits of St. Lucie with Sir Samuel Hood, whom Sir George Rodney, the British admiral in the West Indies had detached to intercept him, Count de Grasse formed a junction with the ships of his sovereign on that station and had a fleet superior to that of the British in the West Indies. De Grasse gave the Americans notice that he would visit their coast in the month of August and take his station in Chesapeake Bay, but that his continuance there could only be of short duration. This dispatch at once determined Washington's resolution with respect to the main point of attack, and as it was necessary that the projected operation should be accomplished within a very limited time prompt decision and indefatigable exertion were indispensable. Though it was now finally resolved that Virginia should be the grand scene of action, yet it was prudent to conceal till the last moment this determination from Sir Henry Clinton, and still to maintain the appearance of threatening New York.
The defense of the strong posts on the Hudson or North river was entrusted to General Heath who was instructed to protect the adjacent country as far as he was able, and for that purpose a respectable force was put under his command. Every preparation of which circumstances admitted was made to facilitate the march to the southward. Washington was to take the command of the expedition and to employ in it all the French troops and a strong detachment of the American army.
On the 19th of August (1781) a considerable corps was ordered to cross the Hudson at Dobbs' Ferry and to take a position between Springfield and Chatham, where they were directed to cover some bakehouses which it was rumored were to be immediately constructed in the vicinity of those places in order to encourage the belief that there the troops intended to establish a permanent post. On the 20th and 21st the main body of the Americans passed the river at King's ferry, but the French made a longer circuit and did not complete the passage till the 25th. Desirous of concealing his object as long as possible, Washington continued his march some time in such a direction as still to keep up the appearance of threatening New York. When concealment was no longer practicable he marched southward with the utmost celerity. His movements had been of such a doubtful nature that Sir Henry Clinton, it is said, was not fully convinced of his real destination till he had crossed the Delaware.
Great exertions had been made to procure funds for putting the army in motion, but, after exhausting every other resource, Washington was obliged to have recourse to Rochambeau for a supply of cash, which he received. {2}
On the 2d and 3d of September (1781) the combined American and French armies passed through Philadelphia, where they were received with ringing of bells, firing of guns, bonfires, illuminations, and every demonstration of joy. Meanwhile Count de Grasse, with 3,000 troops on board, sailed from Cape Francois with a valuable fleet of merchantmen, which he conducted out of danger, and then steered for Chesapeake Bay with twenty-eight sail-of-the-line and several frigates. Toward the end of August (1781) he cast anchor just within the capes, extending across from Cape Henry to the middle ground. There an officer from Lafayette waited on the count, and gave him full information concerning the posture of affairs in Virginia, and the intended plan of operations against the British army in that State.