One of two fortifications built in 1747, the Association Battery was located at the foot of Wharton Street, with 27 cannons aimed out over the Delaware River to stop any French and Spanish privateers who might try to attack the city or its merchant fleet. Britain had been at war with France since 1689. Here in the Pennsylvania colony, Quaker belief in non-violence prevented the city from building any fortifications. That all changed when enemy ships seized 15 Philadelphia merchant vessels in two years. Benjamin Franklin argued for defense in his 1744 pamphlet “Plain Truth.” Three years later, he was among those who defied Quaker opinion and formed the Associators, a militia that would grow to number 1,000 men under arms by 1748. First, a small battery of 13 guns was built at Lombard Street. Shortly thereafter, the larger Association Battery, or “Grand Battery,” was built with 3,000 pounds raised by lottery. Cannon were borrowed from New York and Massachusetts. Pictures of the fort show three buildings enclosed by a crenellated brick or stone wall rising out of the water to a height of perhaps 15 feet. Guards were posted every night, and no boat was allowed to pass between 8 p.m. and 4 a.m. By the time of the Revolutionary War, the Association Battery was described as abandoned, although British troops briefly mounted three cannon there. Today, the site is near Pier 56 South. Archaeologists suggest the fortifications likely survive under the soil.
Sources: Cotter, Roberts & Parrington, The Buried Past: An Archeological History of Philadelphia.
Jackson, Joseph. Encyclopedia of Philadelphia, 1931.