Historic Old New Castle

New Castle is a city in New Castle County, Delaware, six miles (10 km) south of Wilmington, situated on the Delaware River, at the head of Delaware Bay. In 1900, 3,380 people lived here; in 1910, 3,351. According to 2006 Census Bureau estimates, the population of the city is 4,836
The spire on top of the Court House — Delaware's Colonial capitol and first state house — was used as the center of the 12-mile circle forming the northern boundary of Delaware and part of the Mason-Dixon Line. The Delaware River within this radius to the low water mark on the opposite shore is part of Delaware. Thus the Delaware Memorial Bridge was built as an intrastate span by Delaware, without financial participation by neighboring New Jersey.