Wilmington, DE 19810. Phone: 302.543.5454. Fax: 302.327.4200. Directions from Route 202 Concord Pike. Take 202 to Silverside Rd. Right on Silverside Rd. At the second stop light, make a left into the Concord Plaza. Loop around the circle half way and follow the signs to the Quillen Building, which is the RED section..