what is the 12 mile circle in delaware
Twelve-Mile Circle It is nominally a circle with a supposed—yet in fact only approximate and variable—12-mile (19 km) radius,[3] centered in the town of New Castle, Delaware. In 1750, the center of the circle was fixed at the cupola of the courthouse in New Castle. The Twelve-Mile Circle continues into the Delaware River. A small portion of the circle, known as the "Arc Line," also forms part of the Mason-Dixon line, separating Delaware and Maryland. Two other small portions, although not actually demarcated until 1934, form parts of the boundary between the states of Delaware and New Jersey.[4] Although the Twelve-Mile Circle is often claimed to be the only territorial boundary in the United States that is a true arc (excepting those following arcs of latitude), the Mexican boundary with Texas includes several arcs,[5] and many cities in the South (such as Plains, Georgia[6]) also have circular boundaries.