Fort Casimir (1651-1680s) - A Dutch Colonial Fort established in 1651 in present-day New Castle, New Castle County, Delaware. Named Fort Casimir after Count Ernest Casimir of Nassau. Captured by the Swedish in 1654 and renamed Fort Trefalddighet. The Dutch recaptured it in 1655, rebuilt it in 1658 and renamed it Fort New Amstel. Transferred to the British in 1664 and abandoned in the 1680s. Also known as Fort Trinity.
History of Fort Casimir
A Dutch Colonial Fort established under Peter Stuyvesant in 1651 in present-day New Castle, New Castle County, Delaware.
Peter Stuyvesant arrived in 1651 with a fleet of 11 ships and 100 soldiers to construct the new fort, first named Fort Casimir. The garrison at Fort Nassau was transferred to the new fort and Fort Nassau was abandoned.
The fort was captured by the Swedish under Johan Classon Rising on 21 May 1654 who renamed it Fort Trefalddighet. The Dutch under Peter Stuyvesant recaptured it on 26 Aug 1655, rebuilt it in 1658 and renamed it Fort New Amstel.
In 1664 the British forced the Dutch to relinquish control over all New Netherlands and the British established control over the Delaware River Valley. The fort deteriorated under the British and was abandoned in the 1680s.
The fort was said to be located on Sand Hook at the end of Chestnut Street in New Castle, Delaware. The site is now an open area at the end of Chestnut Street identified by a roaside marker and a reader board.
Visited: 20 Apr 2018