Ridgefield. 1 Residential town (1990 pop. 20,919), Fairfield co., SE Conn.; inc. 1709. Industries include nurseries, pharmaceuticals, and electronic research. The battle of Ridgefield (Apr. 27, 1777) was fought there in an effort to stop William Tryon's Tories from retreating after a raid on Danbury. The town has many colonial homes and is noted for its quiet 18th-century charm. 2 Residential borough (1990 pop. 9,996), Bergen co., NE N.J.; inc. 1892. Several corporate headquarters are located there.