A letter was immediately dispatched by D'Estaing to Sullivan, informing him that, in pursuance of orders from the King and of the advice of all his officers, he had taken the resolution to carry the fleet to Boston. His instructions directed him to sail for Boston should his fleet meet with any disaster or should a superior British fleet appear on the coast.

To be abandoned by the fleet in such critical circumstances and not only deprived of the brilliant success which they thought within their reach, but exposed to imminent hazard, caused much disappointment, irritation, and alarm in the American camp. Lafayette and Greene were dispatched to D'Estaing to remonstrate with him on the subject and to press his cooperation and assistance for two days only, in which time they flattered themselves the most Brilliant success would crown their efforts. But the count was not popular in the fleet; he was a military officer as well as a naval commander, and was considered as belonging to the army rather than to the navy. The officers of the sea service looked on him with a jealous and envious eye and were willing to thwart him as far as they were able with safety to themselves. When, on the pressing application of Lafayette and Greene, he again submitted the matter to their consideration, they took advantage of the letter of the admiral's instructions and unanimously adhered to their former resolution, sacrificing the service of their prince to their own petty jealousies and animosities. D'Estaing, therefore, felt himself constrained to set sail for Boston.

The departure of the French marine force left Sullivan's army in a critical situation. It was in a firm reliance on the cooperation of the French fleet that the expedition was undertaken, and its sudden and unexpected departure not only disappointed the sanguine hopes of speedy success, but exposed the army to much hazard, for the British troops under General Pigot might have been reinforced and the fleet might have cut off Sullivan's retreat.

The departure of the French fleet greatly discouraged the American army, and in a few days Sullivan's force was considerably diminished by desertion. On the 26th of August he therefore resolved to raise the siege and retreat to the north end of the island, and took the necessary precautions for the successful execution of that movement.

In the night of the 28th, Sullivan silently decamped and retired unobserved. Early in the morning the British discovered his retreat and instantly commenced a pursuit. They soon overtook the light troops who covered the retreat of the American army, and who continued skirmishing and retreating till they reached the north end of the island, where the army occupied a strong position at a place where the British formerly had a fortified post, the works of which had been strengthened during the two preceding days. There a severe conflict for about half an hour ensued, when the combatants mutually withdrew from the field. The loss of the armies was nearly equal, amounting to between two and three hundred killed or wounded in the course of the day.

On the 30th of August there was a good deal of cannonading, but neither party ventured to attack the other. The British were expecting reinforcements, and Sullivan, although he made a show of resolutely maintaining his post, was busily preparing for the evacuation of the island. In the evening he silently struck his tents, embarked his army, with all the artillery, baggage, and stores, on board a great number of boats and landed safely on the continent before the British suspected his intention to abandon the post. General Sullivan made a timely escape, for Sir Henry Clinton was on his way, with 4,000 men, to the assistance of General Pigot. He was detained four days in the Sound by contrary winds, but arrived on the day after the Americans left the island. A very short delay would probably have proved fatal to their army.

The most sanguine expectations had been entertained throughout the United States of the reduction of Rhode Island and the capture of the British force which defended it, so that the disappointment and mortification on the failure of the enterprise were exceedingly bitter. The irritation against the French, who were considered the authors of the miscarriage, was violent. Sullivan was confident of success; and his chagrin at the departure of the French fleet made him use some expressions, in a general order, which gave offense to D'Estaing.

Washington foresaw the evils likely to result from the general and mutual irritation which prevailed, and exerted all his influence to calm the minds of both parties. He had a powerful coadjutor in Lafayette, who was as deservedly dear to the Americans as to the French. His first duties were due to his King and country, but he loved America, and was so devoted to the Commander-in-Chief of its armies, as to enter into his views and second his softening conciliatory measures with truly filial affection. Washington also wrote to General Heath, who commanded at Boston, and to Sullivan and Greene, who commanded at Rhode Island. In his letter to General Heath he stated his fears "that the departure of the French fleet from Rhode Island at so critical a moment, would not only weaken the confidence of the people in their new allies, but produce such prejudice and resentment as might prevent their giving the fleet, in its present distress, such zealous and effectual assistance as was demanded by the exigency of affairs and the true interests of America;" and added "that it would be sound policy to combat these effects and to give the best construction of what had happened; and at the same time to make strenuous exertions for putting the French fleet, as soon as possible, in a condition to defend itself and be useful." He also observed as follows: "The departure of the fleet from Rhode Island is not yet publicly announced here; but when it is, I intend to ascribe it to necessity produced by the damage received in the late storm. This, it appears to me, is the idea which ought to be generally propagated. As I doubt not the force of these reasons will strike you equally with myself, I would recommend to you to use your utmost influence to palliate and soften matters, and to induce those whose business it is to provide succors of every kind for the fleet, to employ their utmost zeal and activity in doing it. It is our duty to make the best of our misfortunes and not suffer passion to interfere with our interest and the public good."

Writing to General Sullivan he observed: "The disagreement between the army under your command and the fleet has given me very singular uneasiness. The continent at large is concerned in our cordiality, and it should be kept up by all possible means consistent with our honor and policy. First impressions are generally longest retained, and will serve to fix in a great degree our national character with the French. In our conduct toward them we should remember that they are a people old in war, very strict in military etiquette, and apt to take fire when others seem scarcely warmed. Permit me to recommend, in the most particular manner, the cultivation of harmony and good agreement, and your endeavors to destroy that ill-humor which may have found its way among the officers. It is of the utmost importance, too, that the soldier and the people should know nothing of this misunderstanding; or if it has reached them, that means may be used to stop its progress and prevent its effects."

To General Greene, Washington wrote: "I have not now time to take notice of the several arguments which were made use of, for and against the count's quitting the harbor of Newport and sailing for Boston. Right or wrong, it will probably disappoint our sanguine expectations of success and which I deem a still worse consequence, I fear it will sow the seeds of dissension and distrust between us and our new allies, unless the most prudent measures be taken to suppress the feuds and jealousies that have already arisen. I depend much on your temper and influence to conciliate that animosity which, subsists between the American and French officers in our service. I beg you will take every measure to keep the protest entered into by the general officers from being made public. Congress, sensible of the ill consequences that will flow from our differences being known to the world, have passed a resolve to that purpose. Upon the whole, my dear sir, you can conceive my meaning better than I can express it; and I therefore fully depend on your exerting yourself to heal all private animosities between our principal officers and the French, and to prevent all illiberal expression and reflections that may fall from the army at large."