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 County-owned parks and buildings such as County libraries. It does not maintain the water distribution system, which is owned and operated by several private companies. In general, it also does not maintain stormwater management facilities within subdivisions. Access to 911 emergency services is provided by New Castle County through their emergency communications center for all fire/rescue/EMS services throughout the county and the majority of police services, though Newark, Wilmington, and the University of Delaware maintain their own police emergency call centers. New Castle County has its own nationally accredited police department. The New Castle County Police Department is the second