Fort Casimir (New Castle, Delaware)

New Castle · Delaware · Colonial period / Dutch-Swedish conflicts

Quick BriefFort Casimir was erected by the Dutch in 1651, taken by the Swedes in 1654, and retaken by the Dutch under Peter Stuyvesant on September 11, 1655. The English captured it in 1664, Dutch forces briefly regained control in 1673–1674, and the fort was abandoned around 1675.

Coastal defense

History & Significance

Peter Stuyvesant, director-general of New Netherland, ordered the construction of Fort Casimir at Sandhoek, downriver from Fort Christina. Built in 1651 on Stuyvesant's orders to counter the Swedish colony at present-day Wilmington.

The fort featured timber curtain walls, earthen ramparts, a surrounding ditch or moat, corner bastions for cannon fire, and wooden interior buildings for soldiers and supplies. In 1654, Swedish forces from New Sweden marched south and took the garrison without resistance.

The Swedes renamed it Fort Trinity and added a wall along the river armed with six cannons. Stuyvesant led a Dutch force which retook the fort on September 11, 1655, renaming it New Amstel.

English forces under Robert Carr captured it in 1664, with the name translated from Dutch to English as New Castle. By the 1670s, the fort had fallen into ruin, and a new blockhouse replaced it on The Green.