Cobb Island is a small community census-designated place located on a small island at the junction of thePotomac River and the Wicomico River. It is located approximately 45 miles (72 km) south of Washington, D.C., in Charles County, Maryland, and is considered part of the Washington, D.C. MSA. Cobb Island is separated from the mainland by Neale Sound and connected by a 0.11-mile-long (180 m) fixed bridge. As of the 2010 census, the community had a population of 1,166. On December 23, 1900, Reginald Aubrey Fessenden sent and received the first intelligible speech by electromagnetic waves on a pair of masts 50 feet (15 m) high and 1 mile (1.6 km) apart.