SOMERSWORTH, a city of Strafford county, New Hampshire, U.S.A., on the Salmon Falls river, 5 m. N. of Dover, and opposite the town of Berwick, Maine, industrially a part of Somersworth. Pop. (1890) 6207; (1900) 7023 (3166 foreign-born); (1910) 6704. Somersworth is served by the Boston & Maine railroad, and is connected by electric line with Rochester and Dover. The river furnishes good water power, and the city’s chief interests are in the manufacture of cotton and woollen goods, and boots and shoes. It has a public library. In the south-west part is Central Park, lying along the shore of Willand’s Pond. The municipality owns and operates the waterworks. A settlement was established here in the latter part of the 17th century, when the territory was a part of Dover. In 1729 the parish of Summersworth was organized; in 1754 this parish was erected into the town of Somersworth; in 1821 the first company was formed to develop the water-power and establish cotton and woollen mills; in 1849 the southern half of the town was set-off and incorporated as Rollinsford; and in 1893 Somersworth was chartered as a city.
See W. D. Knapp, Somersworth, an Historical Sketch (1894).