NEW CASTLE, a city of New Castle county, Delaware, U.S.A., in the northern part of the state, at the head of Delaware Bay, on a high point of land extending into the Delaware river, 6 m. south of Wilmington. Pop. (1890) 4010; (1900) 3380 (315 foreign born); (1910) 3351. It is served by the Philadelphia, Baltimore & Washington (Pennsylvania System), and (vid Wilmington) the Baltimore & Ohio railways, and by steamship lines connecting with Baltimore, Philadelphia and river ports. The “old” county court house, possibly built by the Swedes, is in New Castle; and there are a public library, the Immanuel Protestant Episcopal Church (partly built in 1689), and several residences of Dutch and colonial types. The city has a good harbour and an excellent river front for manufacturing sites and for shipping; it is included in the customs district of Wilmington. Its industrial establishments include shipyards, rolling mills and steel works, flour-mills, and manufactories of cotton and woollen goods. The shad fisheries are of some importance. In 1651 Governor Peter Stuyvesant of New Netherland established near the place Fort Casimir, as the first determined move in his aggressive policy against the Swedes, who had settled in this vicinity about 1640. The Swedes captured the fort in 1654, but this precipitated the crisis in which New Sweden (Delaware) was lost to the Dutch in 1655. Fort Casimir (renamed Fort Amstel) was made the seat of government of the local Dutch possessions, and in 1657 was placed under the jurisdiction of the City of Amsterdam, under which it remained, though prospering little—disease, famine and fears of English attack causing most of the inhabitants to leave in 1658 and 1659—until just before the English seized the settlements in Delaware in 1664. Under the English the name was changed to New Castle, and trade and commerce prospered; and an arc with a radius of 12 m., having the New Castle court house as a centre, became the northern boundary of the “counties on the Delaware.” New Castle was frequently the meeting place of the colonial legislature, and after the legislative separation of Delaware from Pennsylvania in 1704 it was the seat of administration of the colony until 1777. It was chartered as a city in 1875.