Fort Casimir

Fort Casimir was a Dutch fort built in 1651 on a former barrier island at the end of Chestnut Street to control access to the Delaware River. Today its remains lie buried under a parking lot and houses, with markers near Harmony and Second Streets showing where it once stood.

Peter Stuyvesant founded the fort in 1651 to protect Dutch trade interests against Swedish settlements competing for control along the Delaware. The site changed hands between different rulers multiple times, reflecting its importance as a contested location during the colonial era.

The site marks where Dutch, Swedish, and English colonial powers met and competed for control of the Delaware River region. Visitors walking through New Castle today can see how this cultural crossroads shaped the town's early identity.

The site is marked with plaques at street intersections near downtown New Castle, making it easy to locate during a walk through town. Use these markers as your guide to understand the fort's original position and how the modern street layout relates to its historical footprint.

The fort was named after Polish King Casimir IV, showing how the Dutch colonial administration connected to European powers far beyond North America. This unusual naming choice reveals how global networks shaped the colonial world in unexpected ways.