About the Boston/NYC/Philly/DC Megalopolis The BosWash or Bosnywash megalopolis is the name for a group of metropolitan areas in the northeastern United States, extending from Boston to Washington and linked by economics, transport, and communications. BosWash contains a reported population of 44 million, or 16% of the population of the United States, probably two or more world cities, and four of the world's fifty largest metropolitan areas — Boston, New York, Philadelphia, and Washington — as well as the New York Stock Exchange, the White House and US Capitol, the UN Headquarters, the headquarters of ABC, NBC, CBS, the New York Times and the Washington Post, as well as six of top ten US universities. Travel in the area via Amtrak. Amtrak has several train services that travel the length of the Northeast US corridor. The most frequent service is bounded by Boston in the north and Washington D.C. in the south. The Amtrak service offering is broken down as follows: Acela Express - The most expensive option is the Acela Express train. Although this train may boast nicer accommidations and a slightly better ride (read: smoother), the train is only marginally faster than other service offerings. Metroliner - Regional -