The entrance of France into the war, followed by that of Spain in 1779 and the Netherlands in 1780, produced important changes in the naval aspect of the American Revolution. The Spanish and Dutch were not particularly active, but their role in keeping British naval forces tied down in Europe was significant. The British navy could not maintain an effective blockade of both the American coast and the enemies’ ports. Because of years of neglect, Britain’s ships of the line were neither modern nor sufficiently numerous.

An immediate result was that France’s Toulon fleet under d’Estaing got safely away to America, where it appeared off New York and later assisted Sullivan in the unsuccessful siege of Newport. A fierce battle off Ushant, France, in July 1778 between the Channel fleet under Adm. Augustus Keppel and the Brest fleet under the comte d’Orvilliers proved inconclusive. Had Keppel won decisively, French aid to the Americans would have diminished and Rochambeau might never have been able to lead his expedition to America.

In the following year England was in real danger. Not only did it have to face the privateers of the United States, France, and Spain off its coasts, as well as the raids of John Paul Jones, but it also lived in fear of invasion. The combined fleets of France and Spain had acquired command of the English Channel, and a French army of 50,000 waited for the propitious moment to board their transports. Luckily for the British, storms, sickness among the allied crews, and changes of plans terminated the threat.

Despite allied supremacy in the Channel in 1779, the threat of invasion, and the loss of islands in the West Indies, the British maintained control of the North American seaboard for most of 1779 and 1780, which made possible their Southern land campaigns. They also reinforced Gibraltar, which the Spaniards had brought under siege in the fall of 1779, and sent a fleet under George Rodney to the West Indies in early 1780. After fruitless maneuvering against the comte de Guichen, who had replaced d’Estaing, Rodney sailed for New York.

While Rodney had been in the West Indies, a French squadron slipped out of Brest and sailed to Newport with Rochambeau’s army. Rodney, instead of trying to block the approach to Newport, returned to the West Indies, where, upon receiving instructions to attack Dutch possessions, he seized Sint Eustatius, the Dutch island that served as the principal depot for war materials shipped from Europe and transshipped into American vessels. He became so involved in the disposal of the enormous booty that he dallied at the island for six months.

In the meantime, a powerful British fleet relieved Gibraltar in 1781, but the price was the departure of the French fleet at Brest, part of it to India, the larger part under François-Joseph-Paul, comte de Grasse, to the West Indies. After maneuvering indecisively against Rodney, de Grasse received a request from Washington and Rochambeau to come to New York or the Chesapeake.

Earlier, in March, a French squadron had tried to bring troops from Newport to the Chesapeake but was forced to return by Adm. Marriot Arbuthnot, who had succeeded Lord Howe. Soon afterward Arbuthnot was replaced by Thomas Graves, a conventional-minded admiral.

Informed that a French squadron would shortly leave the West Indies, Rodney sent Samuel Hood north with a powerful force while he sailed for England, taking with him several formidable ships that might better have been left with Hood. Soon after Hood dropped anchor in New York, de Grasse appeared in the Chesapeake, where he landed troops to help Lafayette contain Cornwallis until Washington and Rochambeau could arrive.

Fearful that the comte de Barras, who was carrying Rochambeau’s artillery train from Newport, might join de Grasse and hoping to intercept him, Graves sailed with Hood to the Chesapeake. Graves had 19 ships of the line against de Grasse’s 24. Though the battle that began on September 5 off the Virginia Capes, known as the Battle of the Chesapeake, was not a skillfully managed affair, Graves had the worst of it and retired to New York, thus sealing the fate of Cornwallis’s army at Yorktown.

Graves ventured out again on October 17 with a strong contingent of troops and 25 ships of the line, while de Grasse, reinforced by Barras, now had 36 ships of the line. No battle occurred, however, when Graves learned that Cornwallis had surrendered.

Although Britain subsequently recouped some of its fortunes, by Rodney defeating and capturing de Grasse in the Battle of the Saints off Dominica in 1782 and British land and sea forces inflicting defeats in India, the turn of events did not significantly alter the situation in America as it existed after Yorktown. A new government under Lord Shelburne tried to get the American commissioners to agree to a separate peace, but, ultimately, the treaty negotiated with the Americans was not to go into effect until the formal conclusion of a peace with their European allies.