The Battle of Rhode Island (or Battle of Quaker Hill) took place on August 29, 1778. Continental Army and militia forces commanded by Major-General John Sullivan had been on Aquidneck Island besieging British forces occupying Newport, Rhode Island. They chose to lift the siege and planned to withdraw to the northern part of Aquidneck Island. The British then sortied, supported by recently arrived Royal Navy ships, and attacked the retreating Americans. The battle ended inconclusively, but Continental forces then chose to withdraw further to the mainland, leaving Aquidneck Island including Newport in British hands. The soldiers in combat were about 4,875 in the American army and 2,950 in the British army, for a total of 7,825 making it the largest battle in New England based on numbers.

The battle was the first attempt at cooperation between French and American forces following France's entry into the war. Joint operations against Newport were planned, but frustrated by difficult relations between the commanders and a storm that damaged both the French and British fleets shortly before joint operations were to begin. The battle was also notable for the participation of the 1st Rhode Island Regiment, whose troops were predominantly Black, under the command of Colonel Christopher Greene.

In late 1776, British Major-general Henry Clinton led an expedition from New York City to take control of Rhode Island. Troops of the expedition under Brigadier-general Richard Prescott landed and seized control of Newport, Rhode Island. France formally recognized the United States in February 1778 following the American victory at the Battles of Saratoga in October 1777. Britain declared war on France on March 17, 1778, and the French responded with their own declaration of war against the British on July 10.

France sent Vice-admiral Charles Henri Hector, Count of Estaing with a fleet of 12 ships of the line and 4,000 French Army troops to America in April 1778 in its first major attempt at cooperation with the Americans, with orders to blockade the British fleet in the Delaware River. British leaders had early intelligence that Estaing was headed for America, but political and military differences within the government and navy delayed the British response, and he sailed unopposed through the Straits of Gibraltar. It was not until early June that a fleet of 13 ships of the line left European waters in pursuit, under the command of Vice-Admiral of the Blue John Byron. Estaing's crossing of the Atlantic took three months, but Byron was also delayed due to bad weather and did not reach New York until mid-August.

The British evacuated from Philadelphia to New York City before Estaing's arrival. Their fleet was no longer on the river when the French fleet arrived at Delaware Bay in early July. Estaing decided to sail for New York, but its well-defended harbor presented a daunting challenge. The French and their American pilots believed that Estaing's largest ships would be unable to cross the bar into New York harbor, so French and American leaders decided to deploy their forces against British-occupied Newport, Rhode Island. While Estaing was outside the harbor, Clinton and Vice-Admiral of the Blue Richard Howe dispatched a fleet of transports carrying 2,000 troops to reinforce Newport via Long Island Sound. The troops reached their destination on July 15, raising the size of Major General Robert Pigot's garrison to more than 6,700 men.

American and British forces had been in a standoff on Rhode Island since the British occupation began in late 1776. Major General Joseph Spencer of the Rhode Island defenses had been ordered by Major General George Washington to launch an assault on Newport in 1777, but he had not done so and was removed from command. In March 1778, Congress approved the appointment of Major General John Sullivan to Rhode Island. By early May, Sullivan had arrived in the state and produced a detailed report on the situation. He began logistical preparations for an attack on Newport, caching equipment and supplies on the eastern shore of Narragansett Bay and the Taunton River. Pigot was aware of Sullivan's preparations and launched an expedition on May 25 that raided Bristol and Warren. This destroyed military supplies and plundered the towns. Sullivan's response was to make renewed appeals for assistance, which were reinforced by a Congressional declaration after a second raid on Freetown on May 31.

General Washington wrote to Sullivan on July 17 ordering him to raise 5,000 troops for possible operations against Newport. Sullivan did not receive this letter until July 23, and it was followed the next day by the arrival of Colonel John Laurens with word that Newport had been chosen as the allied target on the 22nd Regiment, and that he should raise as large a force as possible. Sullivan's force at that time amounted to 1,600 troops. Laurens had left Washington's camp on the 22nd, riding ahead of a column of Continental troops (the brigades of John Glover and James Mitchell Varnum) led by the Marquis de Lafayette.

News of the French involvement rallied support for the cause, and militia began streaming to Rhode Island from neighboring states. Half the Rhode Island militia was called up and led by William West, and large numbers of militia from Massachusetts and New Hampshire along with the Continental Artillery came to Rhode Island to join the effort. However, these forces took some time to muster, and the majority of them did not arrive until the first week of August. Washington sent Major General Nathanael Greene, a Rhode Island native and reliable officer, to further bolster Sullivan's leadership corps on July 27. Sullivan had been regularly criticized in Congress for his performance in earlier battles, and Washington urged him to take counsel from Greene and Lafayette. Greene wrote to Sullivan on the matter and reinforced the need for a successful operation.