The march southward thus continued unhampered. They crossed first the Jerseys, "a land of Cockayne, for game, fish, vegetables, poultry." Closen had the happiness to "hear from the lips of General Washington, and on the ground itself, a description of the dispositions taken, the movements and all the incidents of the famous battles of Trenton and Princeton." The young man, who had made great progress in English, was now used by the two generals as their interpreter; so nothing escaped him. The reception at Philadelphia was triumphal; Congress was most courteous; toasts were innumerable. The city is an immense one, "with seventy-two streets in a straight line.... Shops abound in all kinds of merchandise, and some of them do not yield to the Petit Dunkerque in Paris." Where is now the Petit Dunkerque? "Mais où sont les Neiges d'antan?"[42] Women are very pretty, "of charming manners, and very well dressed, even in French fashion." Benezet, the French Quaker, one of the celebrities of the city, is found to be full of wisdom, and La Luzerne, "who keeps a state worthy of his sovereign," gives a dinner to one hundred and eighty guests.

From Philadelphia to Chester, on the 5th of September, Rochambeau and his aides took a boat. As they were nearing the latter city, "we saw in the distance," says Closen, "General Washington shaking his hat and a white handkerchief, and showing signs of great joy." Rochambeau had scarcely landed when Washington, usually so cool and composed, fell into his arms; the great news had arrived; de Grasse had come, and while Cornwallis was on the defensive at Yorktown the French fleet was barring the Chesapeake.[43]

On the receipt of letters from Washington, Rochambeau, and La Luzerne telling him to what extent the fate of the United States was in his hands, the sailor, having "learned, with much sorrow," he wrote to the latter, "what was the distress of the continent, and the need there was of immediate help," had decided that he would leave nothing undone to usefully take part in the supreme effort which, without his help, might be attempted in vain. Having left, on the 5th of August, Cap Français (to-day Cap Haïtien), he had added to his fleet all the available ships he could find in our isles, including some which, having been years away, had received orders to go back to France for repairs. He had had great difficulty in obtaining the money asked for, although he had offered to mortgage for it his castle of Tilly, and the Chevalier de Charitte, in command of the Bourgogne, had made a like offer. But at last, thanks to the Spanish governor at Havana, he had secured the desired amount of twelve hundred thousand francs. He was bringing, moreover, the Marquis de Saint-Simon, with the 3,000 regular troops under his command. De Grasse's only request was that operations be pushed on with the utmost rapidity, as he was bound to be back at the Isles at a fixed date. It can truly be said that no single man risked nor did more for the United States than de Grasse, the single one of the leaders to whom no memorial has been dedicated.

The news spread like wild-fire; the camp was merry with songs and shouts; in Philadelphia the joy was indescribable; crowds pressed before the house of La Luzerne, cheering him and his country, while in the streets impromptu orators, standing on chairs, delivered mock funeral orations on the Earl of Cornwallis. "You have," Rochambeau wrote to the admiral, "spread universal joy throughout America, with which she is wild."[44]

Anxiety was renewed, however, when it was learned shortly after that the French men-of-war had left the Chesapeake, the entrance to which now remained free. The English fleet, of twenty ships and seven frigates, under Hood and Graves, the same Graves who had failed to intercept Rochambeau's convoy, had been signalled on the 5th of September, and de Grasse, leaving behind him, in order to go faster, some of his ships and a number of sailors who were busy on land, had weighed anchor, three-quarters of an hour after sighting the signals, to risk the fight upon which the issue of the campaign and, as it turned out, of the war, was to depend. "This behavior of Count de Grasse," wrote the famous Tarleton, is "worthy of admiration." Six days later the French admiral was back; he had had 21 officers and 200 sailors killed or wounded, but he had lost no ship, and the enemy's fleet, very much damaged, with 336 men killed or disabled, and having lost the Terrible, of 74 guns, and the frigates Iris and Richmond of 40,[45] had been compelled to retreat to New York. Admiral Robert Digby thereupon arrived with naval reinforcements; "yet I do not think," La Luzerne wrote to Rochambeau, "that battle will be offered again. If it is, I am not anxious about the result." Nothing was attempted. This "superiority at sea," Tarleton wrote in his History of the Campaigns, "proved the strength of the enemies of Great Britain, deranged the plans of her generals, disheartened the courage of her friends, and finally confirmed the independency of America."[46] "Nothing," Rochambeau had written in his note-book at starting, "without naval supremacy."

On re-entering the bay de Grasse had the pleasure to find there another French fleet, that of his friend Barras. As a lieutenant-general de Grasse outranked him, but as a "chef d'escadre" Barras was his senior officer, which might have caused difficulties; the latter could be tempted, and he was, to conduct a campaign apart, so as to personally reap the glory of possible successes. "I leave it to thee, my dear Barras," de Grasse had written him on the 28th of July, "to come and join me or to act on thy own account for the good of the common cause. Do only let me know, so that we do not hamper each other unawares." Barras preferred the service of the cause to his own interest; leaving Newport, going far out on the high seas, then dashing south at a great distance from the coast, he escaped the English and reached the Chesapeake, bringing the heavy siege artillery now indispensable for the last operations. The stars had continued incredibly propitious.

The well-known double siege now began, that of Yorktown[47] by Washington and Rochambeau, and that of Gloucester, on the opposite side of the river, which might have afforded a place of retreat to Cornwallis. De Grasse had consented to land, in view of the latter, 800 men under Choisy, whom Lauzun joined with his legion, and both acted in conjunction with the American militia under Weedon.[48] The two chiefs on the Yorktown side were careful to conduct the operations according to rules, "on account," says Closen, "of the reputation of Cornwallis, and the strength of the garrison." Such rules were certainly familiar to Rochambeau, whose fifteenth siege this one was.

From day to day Cornwallis was more narrowly pressed. As late as the 29th of September he was still full of hope. "I have ventured these two days," he wrote to Clinton, "to look General Washington's whole force in the face in the position on the outside of my works; and I have the pleasure to assure your Excellency that there was but one wish throughout the whole army, which was that the enemy would advance." A dozen days later the tone was very different. "I have only to repeat that nothing but a direct move to York River, which includes a successful naval action, can save me ... many of our works are considerably damaged."

Lord Germain was, in the meantime, writing to Clinton in his happiest mood, on the 12th of October: "It is a great satisfaction to me to find ... that the plan you had concerted for conducting the military operations in that quarter (the Chesapeake) corresponds with what I had suggested." The court, which had no more misgivings than Lord Germain himself, had caused to sail with Digby no less a personage than Prince William, one of the fifteen children of George III, and eventually one of his successors as William IV; but his presence could only prove one more encumbrance.