Delaware has a feature that no other state has – a perfect arc for its northern border. Most other colonial borders were either formed by meandering rivers, straight lines from point A to point B, or were carved out by coastal waters. But somebody somewhere made the decision to turn the northern border of Delaware into a smooth arc. What’s up with that?
The original settlers in Delaware territory were Dutch and in fact the state was named after Lord De La Warr who was a Dutch explorer and an early Governor of Virginia colony. The name “Delaware” stuck for the state, the bay, the river and an American Indian people.
When the English ousted the Dutch in 1664, King Charles II of England had a hand in determining Delaware’s borders. It was his idea to carve out the unusual arc shaped northern border and in those days the king had the final say. He declared that the border be set as a 12-mile radius surrounding the Dutch settlement at New Castle.
It took a couple of tries before they had a final version. The center point of the arc was originally set as the steeple of the old Dutch church in town, but was later changed to the courthouse because the end of the arc didn’t correspond well with the straight western border that would later be officially surveyed by Mason and Dixon. The original arc left a sizeable area of “no man’s land” that didn’t have any jurisdiction at all, so with a tweak of the start point they made all of the points line up, and the rounded border remains to this day.