Old Middlesex Canal Toll House

The Old Middlesex Canal Toll House was a barge canal stretching 27 miles between the Merrimack River and the port of Boston and had eight aqueducts. Although it was not the first in the US, it was among the earlier canals and was studied by engineers whom went on to build projects such as the Eerie Canal.  The route for the canal was surveyed in August 1793. The chief engineer in the process of building this canal was a man by the name of Loammi Baldwin.