1. Atlas of historical county boundaries. Delaware, Maryland, and the District of Columbia Publication/Creation: New York : Charles Scribner's Sons, Simon & Schuster Macmillan, 1996 Resource Type: Map Access & Availability: Loading
2. Delaware, District of Columbia, and Maryland Author/Creator: United States. Bureau of the Census. Geography Division Publication/Creation: Washington, D.C. : U.S. Dept. of Commerce, Bureau of the Census, [1983] Resource Type: Map Access & Availability: Loading