The Horn
by Wendel Cassel
Newsletter Article - Friends of White Clay Creek State Park (FWCCSP RECORD, Vol 6, No.1, May 2003, p. 3)
Most area residents have heard about the "wedge," the 714-acre triangular shaped strip of land west of the arc boundary at the northwest corner of Delaware. But have you heard of the "horn"? This area is equally important in defining the northern boundary of Delaware. The original boundary line between Chester County and New Castle County, defined in a 1701 survey, was an arc of 12 miles radius with the center in the city of New Castle. At that time, New Castle, Kent, and Sussex were the three southern counties of Pennsylvania, and most of the boundary markers were temporary in nature. Many of the original survey markers had disappeared by the late 1800s, and significant questions arose as to the actual location of the boundary between Delaware and Pennsylvania.
In 1889, Delaware and Pennsylvania authorized commissioners to define and mark the boundary. The boundary was resurveyed in 1892-3, and a decision was made to use separate arcs (different radii and center points) to define the western and eastern portions of the arc boundary. This was done because of the lack of any markers on the western section, and errors in the original 1701 survey. The western arc that was chosen intersected with an extension of the Mason-Dixon line at the present arc corner approximately 2000 feet east of the previously accepted location, and intersected with the eastern arc just west of Centerville. The commissioners awarded the resulting horn shaped section of land to Pennsylvania and the "wedge" to Delaware. Delaware did not ratify the survey until March 1921 because many of the residents of the "horn" did not want to become part of Pennsylvania. The present boundary between Delaware and Pennsylvania has truncated pyramidal stone markers installed at every half-mile along the arc line starting at the arc corner.
You can read more about the historical background on Delaware's boundaries in the book "East of the Mason-Dixon Line—A History of Delaware Boundaries" by Roger E. Nathan, published by the Delaware Heritage Press. This book can be purchased from the Delaware Heritage Press for $5 by calling 302-577-5046.