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Middlesex Canal Facts

Dates of operation: 1804 to 1851

Type: summit towpath, with lift, guard and tidal locks

Length: 27-1/4 miles

Channel width/depth: 30 feet/ 3.5 feet.

Locks: 15 lift locks, typically 90’ x 10’; 2 extendable-length guard locks (aka raft locks, 90' normal or 670' extended, x 10') and 2 tide locks.

Northern terminus: on the Merrimack River at Middlesex Village, Chelmsford, Massachusetts (now part of Lowell)

Southern terminus: at a mill pond along the Charles River in Charlestown, Massachusetts

Cargo transported: down - stone, iron ore, timber, boards, planks, wood, staves, shingles, ashes, butter, cheese, beef, pork, cider, and grains. Up - foreign manufactured goods, groceries, codfish, mackerel, salt, lime, plaster, etc. Later, raw cotton and wool and finished textiles were added.

Chief engineer: Colonel Loammi Baldwin Sr., with surveying assistance and advice from English canal engineer William Weston; and John Langdon Sullivan.

Owner: Middlesex Canal Company.

History of the Middlesex Canal

During the late 1700s, soon after the end of the Revolutionary War, American economic and political leaders became aware of the commercial and industrial advantages that man-made waterways brought to England and France, and wished to emulate their success in the United States. Such developments were also intended to bind the new republic more closely together, as championed by Alexander Hamilton.

General Henry Knox, Revolutionary War hero and America’s first Secretary of War, was an early canal enthusiast. In 1791, he headed a company to build a 100-mile-long canal between the Connecticut and Charles Rivers. Although it never advanced beyond the planning stage, this attempt prepared Massachusetts’ citizens for other more economical and technically feasible canal projects. Among these was the Pawtucket Canal, built to by-pass dangerous falls of the same name on the Merrimack River.

The Middlesex Canal resulted from efforts by wealthy men of Boston and surrounding towns to tap the natural resources and markets of the Merrimack River Valley in northeastern Massachusetts and south central New Hampshire. James Sullivan, lawyer, attorney general and later Governor of Massachusetts, was an early advocate for and an investor in the Middlesex Canal. He, Loammi Baldwin and other investors joined together to form the Middlesex Canal Company and to serve on its Board of Directors.

Loammi Baldwin was named Supervisor of Construction, i.e., chief engineer for the canal. He received early surveying assistance from English canal engineer William Weston. In 1794, the two men first obtained accurate elevation measurements along survey routes using a "Y-level" and a “station staff”. James Sullivan purchased two such instruments for the company. Thereafter, Weston consulted by letter, contributed lock and section plans, and provided patterns for casting lock parts.

Baldwin adapted hydraulic cement, initially to build three locks at the Merrimack River. He manufactured it by grinding "trass" (an imported volcanic stone) very fine, and mixing it with lime and sand.

“Puddling” , the sealing of a canal bed with layers of hard packed clay, was adjudged too expensive and Baldwin developed an alternative. This entailed packing the earth bottom and sides, then flooding, draining, and repacking until a sufficient seal was achieved. Though inferior to puddling, this solution was acceptable and more affordable.

Baldwin engineered multiple structures. Particularly impressive was the aqueduct that carried the canal across the Shawsheen River. One of eight on the canal, it was 188 feet long, built of wood, and suspended on two abutments and three stone piers; it stood 35 feet above the river.

In his 1808 national survey of roads and canals, Albert Gallatin called the Middlesex Canal "the greatest work of the kind which has been completed in the United States". The early success of the Middlesex Canal helped to inspire the construction of canals in other parts of the United States, particularly the Erie Canal. States such as New York sent official delegations to inspect the successful Middlesex. The Middlesex also served as a school of practical experience for early engineers and is considered by many to be the birthplace of American Civil Engineering.

Timber and masts from New Hampshire forests were important items of commerce. These were bound into rafts at the points of origin, usually joined end-to-end with other rafts into “bands”, and floated on river and canal to Boston, Medford and other towns. 

Boats, ranging from 45 to 75 feet in length and 9 to 9-1/2 feet in beam, were used. On the river, these boats were poled, rowed and sometimes sailed; on the canal, they were drawn by a horse, often rented from the canal company livery.

In about 1804, a tidal lock was constructed to provide access into the Charles River. A fixed line, weighted so that it normally sank to the bottom, was extended across the river to the Boston shore. Boatmen used this line to warp their boats across the river. 

In 1805, a branch canal with two lift locks (one a tidal lock) was constructed in Medford to serve ship-building firms along the Mystic River.

In 1808, John Langdon Sullivan became the Agent for the Middlesex Canal. He devised effective procedures for those who operated and used the canal, for maintaining it and for collecting fees. He also oversaw construction of several Merrimack River Canals and the operation and maintenance of the entire system thereafter.

In about 1810, the Boston Mill Pond Company (MPC) constructed a cross-Boston canal into Haymarket Square. Beyond this, Boston's harbor was reached through "Mill Creek", a natural waterway that had been enlarged.

At about the same time, docks and canals were constructed in East Cambridge, across the Charles River from Boston. Named the Broad, South, Portland (or North), and Lechmere Canals, these linked East Cambridge and Cambridgeport, through the Middlesex Canal, to the commerce of the Merrimack Valley.

At the north end, the Middlesex Canal connected with the Merrimack River. By 1815, eleven short canals, constructed around discrete falls and rapids, made the river navigable as far north as Concord, New Hampshire. Downstream, the river had already been made navigable by the Pawtucket Canal, built by “The Proprietors of Locks and Canals on Merrimack River”. All together, the canal system extended commercial transportation between Concord and Boston, and to tidewater and beyond. Tributary canals soon provided access to several villages and industrial sites. At its peak, the complete river navigation and canal complex exceeded 100 miles in length.

In 1811, Sullivan formed the Merrimack Boating Company (MBC) which became the principal long-haul shipper between Boston and Concord NH. Sullivan developed several generations of steam tow boats that were used to expedite shipping on the river. Towboat development garnered Sullivan 16 patents, including the first ever issued for a towboat, eight to Samuel Morey and one to Michael Morrison.

The period of the canal system’s greatest prosperity occurred between 1819 and 1833. 

In 1830, Massachusetts chartered the Boston and Lowell Railroad, which became the mechanism of the canal’s demise. As successive rail lines extended northward, to Lowell in 1835, Nashua in 1838, and finally to Concord in 1842, they progressively won over the canal’s customers. Although it ultimately succumbed, the Middlesex and Merrimack River Canal complex competed with the railroads for a decade and a half. 

Commercial traffic on the Middlesex Canal ended when the final toll was collected on November 23, 1851. The Merrimack River Canals were legally abandoned in 1855 and the Middlesex Canal Company was dissolved in 1860.

Special Features

Floating towpaths, extendable-length guard locks (aka “raft locks”), and early use of the law of Eminent Domain.

The canal employed two floating towpaths. Initially, a slender, 150 foot long floating towpath across the Concord River constrained boats and rafts to be drawn across manually, while another of the crew led the tow animal over the millpond dam. When enlarged in 1809, the new floating towpath enabled draft animals to pull canal boats and rafts directly across the river.

Another floating towpath was briefly used at the millpond in Charlestown. It was not adequate and was soon replaced by a bank side towpath.

In 1809, a second set of lower lock gates were built at each of the Concord River guard locks, to extend the usable lock-length by several hundred feet. These enabled "bands" of log rafts (many rafts lashed end to end) to be taken across the river without disassembly and reassembly of the bands.

The Middlesex Canal Company used the law of Eminent Domain to acquire a small portion of the land needed to build the canal.

Other features included 8 aqueducts; 48 bridges, taverns, stables, landings (controlled cargo transfer points), mills and other facilities.

During the construction phase, special dump carts were designed to facilitate removal of earth from the dig sites. These could run on land, or on wooden rails to reduce the manpower required to use them.

Suggestions for further Reading

Samuel P. Hadley, Boyhood Reminiscences of Middlesex Village (with Map), Contributions of the Lowell Historical Society, Volume 1, April 1913; pp. 180 to 286

Christopher Roberts, The Middlesex Canal. Cambridge, Mass: Harvard University Press, 1938.

Lewis M. Lawrence, The Middlesex Canal. Boston Mass. 1942. Manuscript reprinted in 1997 by the Middlesex Canal Association.

Mary Stetson Clark, The Old Middlesex Canal. Easton, Pa: Canal History and Technology Press, 1986.

Bert VerPlanck, Middlesex Canal Guide and Maps, Billerica Mass: The Middlesex Canal Association, 1996

Carl and Alan Seaburg and Thomas Dahill, The Incredible Ditch: A Bicentennial History of the Middlesex Canal. Medford, Mass: Anne Miniver Press, Medford Historical Society, 1997

Both Pawtucket and Middlesex Canal Companies’ records are located at the Mogan Center in Lowell; and the latter at the Massachusetts Historical Society in Boston, and Baker Library at Harvard University, Cambridge; all in Massachusetts.

Exhibits, and some of the same records, can be seen at the Middlesex Canal Museum in North Billerica, Mass.

Links

Middlesex Canal Association www.middlesexcanal.org

Lowell National Historic Park www.nps.gov/lowe