The Boott Cotton Mills complex became one of the finest examples of mill architecture in the United States through many decades of expansion and adaptation. In the late 1830s, four mill buildings were constructed between the Eastern Canal and Merrimack River, with open space around them because of the fear and danger of fire. In the 1840s, the introduction of sprinkler systems made expansion possible, and the original mills were connected to form two larger buildings while a fifth mill was added, causing the open space to vanish. After the Civil War, the widespread use of steam power brought another round of construction in which four more mills were added and the earlier buildings were expanded. As the millyard eventually became completely enclosed, views of the river, city, and canals disappeared.

Photo: Barry Swackhamer

Photo: Van Slyck and Company, Boston

Photo: William Fischer, Jr.

Photo: William Fischer, Jr.

Photo: William Fischer, Jr.