CompuServe.com RCN - Digital Cable TV, High-Speed Internet Service & Phone in Boston, Chicago, New York City, Philadelphia, Washington, D.C. and the Lehigh Valley. Census Bureau "Annual Estimates of the Resident Population for the United States, Regions, States, and Puerto Rico: April 1, 2000 to July 1, 2008" Check |url= value (help). United States Census Bureau. Retrieved 2009-02-06.  "Elevations and Distances in the United States". U.S Geological Survey. April 29, 2005. Retrieved 2006-11-03.