In 2000, the US Census noted that Somerville, MA was the most densely populated municipality in New England, and among the most dense in the United States. Somerville was established as a town in 1842, when it was separated from Charlestown. Unlike most towns and cities that were established in the colonial days or afterward, the name Somerville has no meaning, in fact the Somerville Historical Society found that Somerville was a "purely fanciful name". Among other things, Somerville is also known for the invention of Fluff, the marshmallow creme. Somerville is also known for its Prospect Hill, where one of the first American flags was raised on January 1, 1776 as well as its Winter Hill Gang whose members have included notorious Boston gangster James "Whitey" Bulger and hitman Stephen "The Rifleman" Flemmi.