Somersworth, a town of Strafford co., New Hampshire, on the Salmon Falls river, which separates it from Maine, and on the Eastern and Boston and Maine railroads, 33 m. E. of Concord and 65 m. N. of Boston; pop. in 1870, 4,504. It is the fifth town in the state in point of manufactures, the principal village being Great Falls, near the falls of that name in Salmon Falls river. The Great Falls manufacturing company, with a capital of $1,500,000, controls the water power (reckoned at 3,200 horse power), and employs about 1,800 hands, manufacturing about 20,000,000 yards of cotton goods annually. The Great Falls woollen company manufactures cassimeres, and the Somersworth machine company stoves and castings of all kinds; these have a capital of $100,000 each. There are several smaller manufactories, including a flour mill with a capital of $30,000. The village contains three banks, two hotels, about 60 stores, 15 schools, a public library of 6,000 volumes, a weekly newspaper, and six churches.