Heritage trolley lines have long been a mainstay of American cities since the Bicentennial of 1976, and cities such as Seattle, Dallas, and New Orleans alike have seen their heritage streetcars run well into the 21st Century on their own dedicated routes. With heritage streetcars come the possibility of urban revitalization and that nasty word, "gentrification", but don't underestimate the power of a heritage streetcar. Even the filthiest and most industrialized city can find itself beautified with a street railway, and no heritage trolley exemplifies this more than the longest-running heritage streetcar in America, the Lowell Street Railway in Lowell, Massachusetts.