The Battle of Red Bank, also known as the Battle of Fort Mercer, was fought on October 22, 1777, during the American Revolutionary War. A British and Hessian force was sent to take Fort Mercer on the New Jersey side of the Delaware River just south of Philadelphia, but was defeated by a smaller force of Continental Army troops. Although Fort Mercer ultimately fell to the British a month later, the victory at the Battle of Red Bank served as a much-needed morale boost to the Patriot cause, delaying British plans to consolidate gains in Philadelphia, and relieving pressure on Washington's Continental Army, which was embedded north of Philadelphia. In the fall of 1777, Colonel Christopher Greene, the commander of the American forces in Mercer set up headquarters in the Whitall House. He decided that the family’s apple orchard was the ideal location for a defensive fort, so the orchard was razed, and Fort Mercer was built. Fort Mercer was part of the system of the Delaware River forts. A triple row of chevaux de frise extended between Fort Mifflin, Pennsylvania and Fort Mercer. the fort was a large earthwork that had 14 cannon mounted in it. The fort was protected on the land side by a ditch and abatis. Trenches were dug around the perimeter of the fort. Greene, the fort commander, had a garrison of 400 Rhode Island troops.

After the capture of Philadelphia and of the failure of the American surprise attack against the British at the Battle of Germantown, the Americans tried to deny the British use of the city by blockading the Delaware River. To that end, two forts were constructed commanding the river. Von Donop, whose attack had been repulsed at the Second Battle of Trenton, was eager to avenge what he considered to be a humiliation. Donop soon realized the arduous task that was entrusted to him and asked Howe in vain for more artillery, but Howe ordered him to wait for the British fleet to come up river to assist him, and that if Donop could not capture the fort the British would, an order that apparently belittled Donop. With five British men-of-war in the river to support the attack, von Donop was convinced that the fort would be in his hands by nightfall. To make matters worse for the British and Hessians, the six British men-of-war were engaged by smaller American gunboats. During the engagement, two of the ships, the 64-gun ship-of-the-line HMS Augusta and the sloop of war HMS Merlin ran aground on a shoal trying to avoid underwater chevaux-de-frise or stockades, placed in the river to pierce the hulls of intruding British warships. Frustrated by the failure to capture Fort Mercer, Howe ordered the Hessian regiments withdrawn from New Jersey while he made plans to attack Fort Mifflin by a massive artillery bombardment. By early November, the British artillery batteries on Providence Island were complete, and a number of warships were available in support.