New Castle County, Delaware On November 6, 1674, New Amstel was made dependent on New York Colony, and was renamed New Castle on November 11, 1674. On September 22, 1676, New Castle County was formally placed under the Duke of York's laws. It gained land from Upland County on November 12, 1678. On June 21, 1680, St. Jones County was carved from New Castle County. It is known today as Kent County, Delaware. On August 24, 1682, New Castle County, along with the rest of the surrounding land, was transferred from the Colony of New York to the possession of William Penn, who established
New Castle County, Delaware to Lower Alloways Creek Township, New Jersey. New Castle County, like all of Delaware's counties, is subdivided into hundreds. New Castle County is apportioned into ten hundreds: Brandywine, Christiana, Wilmington (the city of Wilmington, which, by law, is a hundred in itself), Mill Creek, White Clay Creek, Pencader, New Castle, Red Lion, St. Georges and Appoquinimink. The highest natural point in Delaware, Ebright Azimuth at 451 feet (137 m), is located in New Castle County. The Chesapeake and Delaware Canal was built through New Castle County, and adjoining Cecil County, Maryland, between 1822 and 1829. As of the census of