It provided horsecar service for passengers traveling between Charlestown/lower Middlesex County and downtown Boston.
The Middlesex Railroad was founded on April 29, 1854 by an act of the Massachusetts state legislature, with Asa Fisk, Richard Downing, and David Kimball being the original corporators.
[3] In its first years the Middlesex recorded no direct passenger traffic as its road was leased to the Malden and Melrose Railroad, which furnished the equipment and handled operations.
[5] At the same time, the company stepped into leases formerly held by the Malden and Melrose, by which it additionally gained control of the lines of the Medford and Charlestown, the Somerville Horse, and the Boston and Chelsea railroads.
[11] In August 1886 the Middlesex and the Highland Street Railway agreed to consolidate and form the Boston Consolidated Street Railway, with Charles Edward Powers of the Middlesex serving as president and Moody Merrill of the Highland as vice president.