Captain Thomas Machin

Thomas Machin was born in England around 1744 and trained as an engineer and millwright before emigrating to America in the years before the Revolution. His technical background made him valuable to the Continental Army from the outset of the war, and he served in various engineering capacities before his role at West Point brought him his most lasting contribution to the American cause. He participated in early attempts to obstruct the Hudson River to British naval passage — a strategic priority recognized by American commanders from the beginning of the war, since British control of the Hudson would effectively divide the colonies geographically.

Machin's principal achievement was the design and installation of the Great Chain across the Hudson River at West Point in 1778. The chain — composed of massive iron links forged at the Sterling Iron Works in New York, connected by swivels and supported on log floats — stretched from the West Point shore to Constitution Island on the opposite bank, a distance of roughly five hundred yards. The individual links weighed approximately one hundred pounds each, and the total assembly, at approximately sixty-five tons, was one of the largest single iron objects produced in colonial North America. Machin oversaw the technical aspects of the forging, the transport of the chain sections to the river, and the assembly and deployment on the water. The chain was accompanied by a boom of logs to reduce the velocity of any ship attempting to force a passage, and the whole assembly was anchored to large iron staples driven into the riverbank. British commanders evaluated the obstacle and concluded that passing it under fire from the West Point batteries was not a viable operation.

Machin continued to serve the Continental Army in engineering roles through the remainder of the war, participating in various construction and fortification projects that rarely achieved the historical visibility of the chain. After the war he worked as a surveyor in New York, contributing to the mapping of the state's interior, and held local offices in the communities where he settled. He died in 1816. The Great Chain itself, maintained through the entire war, was removed after peace was concluded and sections of it survive today — displayed at West Point's Trophy Point as a tangible relic of the engineering ingenuity that helped protect the Hudson Highlands through the war's darkest years.