ANSONIA, a city of New Haven county, Connecticut, U.S.A., coextensive with the township of the same name, on the Naugatuck river, immediately N. of Derby and about 12 m. N.W. of New Haven. It is served by the New York, New Haven & Hartford railway, and by interurban electric lines running N., S. and E. Pop. (1900) 12,681, of whom 4296 were foreign born; (1910 census) 15,152. Land area about 5·4 sq. m. The city has extensive manufactures of heavy machinery, electric supplies, brass and copper products and silk goods. In 1905 the capital invested in manufacturing was $7,625,864, and the value of the products was $19,132,455. Ansonia, Derby and Shelton form one of the most important industrial communities in the state. The city, settled in 1840 and named in honour of the merchant and philanthropist, Anson Green Phelps (1781–1853), was originally a part of the township of Derby; it was chartered as a borough in 1864 and as a city in 1893, when the township of Ansonia, which had been incorporated in 1889, and the city were consolidated.