Potomac is a census-designated place in Montgomery County, Maryland, United States, named after the nearby Potomac River. In 2013, CNNMoney listed Potomac as the most affluent town with more than 25,000 residents in the United States, based on median household income.
Wikipedia

Maryland is a Mid-Atlantic state that's defined by its abundant waterways and coastlines on the Chesapeake Bay and Atlantic Ocean. Its largest city, Baltimore, has a long history as a major seaport. Fort McHenry, birthplace of the U.S. national anthem, sits at the mouth of Baltimore?s Inner Harbor, home to the National Aquarium and Maryland Science Center.
Wikipedia

The U.S. is a country of 50 states covering a vast swath of North America, with Alaska in the northwest and Hawaii extending the nation?s presence into the Pacific Ocean. Major Atlantic Coast cities are New York, a global finance and culture center, and capital Washington, DC. Midwestern metropolis Chicago is known for influential architecture and on the west coast, Los Angeles' Hollywood is famed for filmmaking.

Wikipedia