Nike Missile Philadelphia Defense Area
In the early 195Os, a dozen gun batteries positioned 6 to 7 miles from the
center of the city protected the "City of Brotherly Love." In the mid-1950s
the Philadelphia District of the Corps of Engineers supervised the
construction of a circle of 12 Nike Ajax sites averaging 25 miles from center
city. Sites on the Pennsylvania side of the Delaware River included:
(PH-82) Valley Forge/Paoli
(PH-91) Worchester/Center Square
(PH-75) Edgemont/Delaware City
Headquarters facilities were located at Swarthmore.
Sites PH-75 and PH-99 were upgraded to launch Nike Hercules missiles. Following this modernization, the remaining Nike Ajax sites were deactivated from 1961 to 1963. Site PH-75 was deactivated in 1968; PH-99 stayed on duty until 1971. These batteries were manned by both Regular Army and Pennsylvania Army National Guard units. Command and control functions were hosted by a "Missile Master" facility based at Pedricktown, New Jersey.
The contributions of Philadelphia's defenders were recognized on April 24, 1963, as Mayor H.J. Tate presided over a ceremony declaring that spring day in Philadelphia as "ARADCOM Day."