Encyclopedia of Greater Philadelphia | Brickmaking and ...
Philadelphia sat atop a bed of highquality brick clay just below the surface, so extensive that even after two centuries of mining it still provided enough clay to produce more than 200 million bricks a year by the end of the nineteenth century. The best quality brick clay was in the "Neck," between the Delaware and Schuylkill Rivers. New Jersey had wideranging deposits of clay running ...