Sullivan Square

Sullivan Square is a traffic circle located in the Charlestown neighborhood of Boston. The Sullivan Square MBTA station is located to the west of the square. Adjacent to the East Somerville area of Somerville, Sullivan Square is named after James Sullivan, an early 19th century Governor of Massachusetts.

In the early 2000s, the Sullivan Square Overpass was dismantled, which left a stub approach to Route 99.

Sullivan Square stands on what was once a narrow neck of land referred to as the Charlestown Neck, an area that was originally a thin strip of land connecting the Charlestown Peninsula with present-day East Somerville. Being in a narrow place between larger land masses made Sullivan Square a place where transportation routes naturally converged, and various transportation facilities developed here over the years.

Of particular note was the construction of the Middlesex Canal which traveled 27 miles from Lowell to terminate at the Mill Pond in Charlestown, passing directly through where the Sullivan Square traffic circle stands today. Completed in 1803, the canal was considered a major engineering feat at its time. However, the Boston and Lowell Railroad, completed in 1835, captured much of the freight business, and the canal ceased operation by 1853. The Boston and Lowell and the Fitchburg, the earliest railroads to pass through Somerville, did not come through this area of the city, but in 1842 the Boston and Maine Corporation opened a station near Sullivan Square. This led to the construction of a residential enclave for commuters to Boston. New streets were laid out, such as Mt. Vernon Street and Mt. Pleasant Street, and small lots were plotted out along them.

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