The Middlesex Canal was a 27 mile long transportation canal that connected the Merrimack River in Lowell (initially East Chelmsford) with Boston.  Built between 1793 to 1803, the canal was one of the first of its kind in the United States, served as a model for the Erie Canal, and operated until 1851.  Listed on the National Register of Historic Places in 1972, a second designation known as the Middlesex Canal Historic and Archeological District was listed in 2009.

In addition, the Middlesex Canal was designated as a Historic Civil Engineering Landmark by the American Society of Civil Engineers in 1967.