27. Right in the Crook

The boundary between these two states is delineated by natural features, specifically along the river’s edge. Within a twelve-mile circle centered around the town of New Castle, Delaware, the boundary follows the low water mark of the Delaware River on the eastern, or New Jersey, side.

Beyond this circle, the border is defined by the thalweg, or main channel of navigation, in the Delaware River and Delaware Bay. This boundary arrangement showcases the historical and geographical significance of the Delaware River as a natural dividing line between these neighboring states, underscoring the importance of waterways in shaping territorial boundaries.