One of the largest conurbations in the world is located along East Coast of the United States, and has been called the Atlantic Seaboard Conurbation (ASC). The ASC extends over 1,000 kilometers (600 miles) and includes the major economic, governmental, and cultural centers of Boston, Massachusetts; New York, New York; Philadelphia, Pennsylvania; Baltimore, Maryland; and Washington, District of Columbia.  BosWash,” as the Atlantic megalopolis is known, is inhabited by 49.6 million people (2000 ), about the 17 % of the US population.    America 2050 projections expect the area to grow to 58.1 million people by 2025. The individual cities and the smaller cities in between should be considered in any way a megalopolis because their level of integration.  French geographer Jean Gottmann popularized the term in his 1961 book Megalopolis: The Urbanized Northeastern Seaboard of the United States.In fact, his conclusion was that the various cities contained in the region, especially Washington, D.C.,Baltimore, Philadelphia, New York City, and Boston,are so uniquely tied to each other through their suburban zones, that it’s correct to speak about a unified super-city: a megalopolis.