New Castle County, Delaware New Castle County Police and Emergency Medical Services Division Headquarters and the emergency communications center supporting 911 services. The present building opened in 2007 with a construction cost of . The Headquarters occupied a former elementary school building on the same site prior to erection of the current building. New Castle is a Democratic-leaning county. Because its population is almost double the combined population of Kent and Sussex, the winner in New Castle County has also won Delaware overall in each of the last seventeen presidential elections. In 1992, 2000, 2004 and 2016, the Republican candidate carried Kent and Sussex,
New Castle County, Delaware James, was granted this land by King Charles II. One of the first acts by the Duke was to order removal of all Dutch from New Amsterdam; he renamed New Amstel as New Castle. In 1672, the town of New Castle was incorporated and English law ordered. However, in 1673, the Dutch attacked the territory, reclaiming it for their own. On September 12, 1673, the Dutch established New Amstel in present-day Delaware, fairly coterminous with today's New Castle County. The establishment was not stable, and it was transferred to the British under the Treaty of Westminster on February 9, 1674.