sentences:  Northeast megalopolis
  
  The Northeast megalopolis (also Boston–Washington corridor or Bos-Wash corridor) is the most populous megalopolis located entirely in the United States, with over 50 million residents, as well as the most urbanized megalopolis in the United States and the megalopolis with the world's largest economic output.Located primarily on the Atlantic Ocean in the Northeastern United States, with its lower terminus in the upper Southeast, it runs primarily northeast to southwest from the northern suburbs of Boston, Massachusetts, to the southern suburbs of Washington, D.C., in Northern Virginia.