MASDIX North Line Mile 86, 1766, DE MD, is an 11.75-inch by 11.25-inch Portland Stone (oolitic limestone) shaft that projects 14 inches. It was set by Charles Mason and Jeremiah Dixon in 1766 to demarcate their 1765 survey of the North Line. It is located about 315 feet west of the centerline of Chippenham Drive, about 2.4 miles northwest downtown Newark, DE, about one miles south of the MD-DE-PA tri-state boundary intersection point (at PID = JU3841), and on the Cecil County, MD, – New Castle County, DE, boundary line. It is 86.2 miles north of the southwest corner of Delaware at BM 0 = MD-DE CORNER, PID = HU1800. The boundary stone is in both the National Geodetic Survey (NGS) and Geocaching databases as BOUNDARY MONUMENT 86 DEL MD, at PID = JU3845: (
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The stone is an intermediary boundary mile marker (does not mark a mile point divisible by 5). The cut M on the west face, the cut P on the east face and the fluting are all very well preserved, though there is a large chip missing from the upright element of the P. The top retains some of its original pyramidal shape. The stone is erect and stable. The stone is in a wooded area with moderate undergrowth, about 315 feet west of Chippenham Drive. It is accessible through the yard of the private residence at number 13. The area once served as a Boy Scout camp, but has been unused for several years. It will be developed with new homes in the very near future.
Mason and Dixon first surveyed this position on or about June 5, 1765. The stone was set on or about November 5, 1766 under their direct supervision. The US Coast and Geodetic Survey monumented the stone 1961 as BOUNDARY MONUMENT 86 DEL MD, PID = JU3845.
To reach from Exit 100B off Interstate Highway 95 south of Newark, DE, go northeast on MD State Highway 279/DE State Highway 3 for about 2.5 miles to the intersection with Casho Mills Road. Turn left and go northwest and north on Casho Mills Road and New Casho Mills Road for about 1.4 miles to the intersection with DE State Highway 273 (Nottingham Road). Turn left and go northwest on DE State Highway 273 for about 0.7 miles to the intersection with Wedgewood Road. Turn right and go north on Wedgewood Road for about 0.7 miles to the intersection with Bennington Drive. Turn left and go west on Bennington Drive for about 0.1 miles to the intersection with Chippenham Drive. Turn right and go north on Chippenham Drive for about 0.2 miles to house number 13 on the left. With permission of the home owner, start at the southwest corner of the house and pack southwest through the yard for about 75 feet to the wooded area. Continue southwest and south for another 100 feet to the stone.
HISTORY OF THE NORTH LINE
The North Line forms a small portion of the boundary line between Delaware and Maryland. It is a 3.6-mile long line that runs due north from a point near the western-most extent of the Twelve-Mile Circle boundary line centered on the courthouse at New Castle, DE, to the intersection of the Maryland, Delaware and Pennsylvania boundaries at the northeast corner of Maryland. It is marked with six surviving historical stones (sharing two with the Arc Line and one with the West Line) that are described below.
In 1750, after 70 years of dispute and failed negotiations between the proprietors of Delaware and Pennsylvania (the Penn Family) and the proprietors of Maryland (the Calvert Family), the Court of Chancery (equity) ruled on the boundary definitions for those three colonies. Among the Court’s determinations were (paraphrased):
a. The Twelve Mile Circle forming the northern boundary line of Delaware with Pennsylvania was to be centered on the cupola of the New Castle courthouse and measured horizontally as a radius,
b. The southwest corner of Delaware was to be the “Middle Point” of a line to be run from Cape Henlopen on the Atlantic coast (the modern Fenwick Island) across the Delmarva Peninsula,
c. The western boundary of Delaware was to be a line (the “Tangent Line”) run northerly from the Middle Point to a point tangent (the “Tangent Point”) with the Twelve Mile Circle,
d. The Tangent Line was to be run due north (the “North Line”) from the Tangent Point until it intersected a line of constant latitude (the “West Line”) fifteen miles south of the most southerly point in Philadelphia,
e. If any portion of the Twelve Mile Circle extended west beyond the North Line, the area within the Circle would remain Delaware territory (it did, and the portion of the colony’s boundary that the extending Circle formed would later be known as the “Arc Line”), and,
f. The West Line, constituting the northern boundary line of Maryland with Pennsylvania, was to be a parallel of constant latitude fifteen miles south of the most southern point in Philadelphia, and was to extend from the northern end of the North Line westward to a point equal to five degrees of longitude west of the Delaware River.
The Court appointed four local surveyors to run the Transpeninsular Line and, then, to run the Tangent Line northerly to the Twelve-Mile Circle boundary line. In 1750-1751, the surveyors, John Watson and William Parsons of Pennsylvania and John Emory and Thomas Jones of Maryland, ran and marked the Transpeninsular Line. In 1760, the Court ratified the Middle Point. Mr. Watson and the other three surveyors then ran a twelve-mile radius from the New Castle courthouse and established the “Tangent Point”, where a line run a few degrees west of north from the Middle Point would intersect the Twelve-Mile Circle boundary line. In 1761, the surveyors began to run the Tangent Line but, after about two years’ work, the task proved to be beyond their technical abilities. In August, 1763, the proprietors of the two colonies engaged Charles Mason and Jeremiah Dixon to complete this line, and to survey and mark all the boundary lines between Maryland and the Penns’ two colonies.
In 1764, Mason and Dixon accepted the colonial surveyors’ determinations of the Middle Point and the Tangent Point and ran the Tangent Line. In June, 1765, Mason and Dixon ran a line due north from the Tangent Point and established both the Arc Line and the North Line segments of the Delaware-Maryland boundary line. That month, they also marked the Arc Line with five unmarked dark gray gneiss stones. In November, 1766, they added a standard limestone intermediate mile stone. This last stone also served to mark the 83rd mile north of the southwest corner of Delaware.
Mason and Dixon were assisted by three colonial surveyors: Joel Bailey, Jonathan Cope and William Darby. They also engaged the services of a small army of axmen, teamsters and other laborers.
In 1849, Lt. Col. J. D. Graham, US Corps of Topographical Engineers (USCTE), re-surveyed the Arc Line and the North Line. The USCTE survey set new stones at the north and south ends of the North Line.
The North Line was marked with eight historical stones, six of which survive:
1. At the south end of the line, a stone with PID = JU3846 (MD SEL BDRY INTERSEC STONE 2). It is an 1849 USCTE stone, and is known locally as the “Prism Stone”. It is a three-sided granite shaft that projects about 24 inches. It has a cut “D” on the southeast face, a cut “M” on the west face, and a cut “P” on the north face.
2. At the Prism Stone, a roughly-dressed stone with no PID, but identified by the Delaware Geological Survey as the stone that Mason and Dixon set on this spot in June, 1765. It is an 8 x 12 x 44 dark gray gneiss stone, and is lying on its side in a wood cradle a few feet from the Prism Stone.
3. About 0.6 miles north of the Prism Stone, a stone with PID = JU3853 (BOUNDARY MONUMENT 84 DEL MD). It is an intermediate mile marker set by Mason and Dixon in November, 1766. It is a 12-inch by 12-inch Portland Stone shaft that projects about 29 inches, and has a cut “M” on the west face and a cut “P” on the east face.
4. About 1.6 miles north of the Prism Stone, a stone with PID = JU3844 (BOUNDARY MONUMENT 85 DEL MD). It is an intermediate mile marker set by Mason and Dixon in November, 1766. It is a 12-inch by 12-inch Portland Stone shaft that projects about 29 inches, and has a cut “M” on the west face and a cut “P” on the east face (which is uncharacteristic of a stone for mileage divisible by five – such stones were normally crown stones).
5. At an unknown location, an unmarked, dark gray gneiss stone set by Mason and Dixon on June 18, 1765. This stone has been lost.
6. At about 2.6 miles north of the Prism Stone, a stone with PID = JU3845 (BOUNDARY MONUMENT 86 DEL MD). It is an intermediate mile marker set by Mason and Dixon in November, 1766. It is a 12-inch by 12-inch Portland Stone shaft, and has a cut “M” on the west face and a cut “P” on the east face.
7. At the north end of the North Line, about 3.6 miles north of the Prism Stone, a stone set by Mason and Dixon on June 18, 1765, to mark the intersection of the North Line and the West Line. Presumably, it was a double crown stone like that standing at the southwest corner of Delaware (at PID = HU1800). Unfortunately, this stone has been lost.
8. At the north end of the North Line, about 3.6 miles north of the Prism Stone, a stone with PID = JU3841 (BOUNDARY MON 87 DE MD PA = RM2). It is a 14-inch by 14-inch granite shaft that projects about 24 inches. It has an inscribed “P” on the north and east faces, and an inscribed “M” on the south and west faces. Additionally, “1849” is inscribed on the north face.
Although the North Line is a distinct boundary segment from the Tangent Line, four stones (Boundary Monuments 84 through 87, inclusive) are named for their distance in miles north of the stone at PID = HU1800 at the southwest corner of Delaware (as if the Tangent Line, Arc Line and North Line formed a single, straight boundary line).
According to the 1994 boundary agreement between Delaware and Maryland, the surviving Mason-Dixon and Graham Survey stones continue to mark this portion of the two states’ common boundary line.
References: Mason, Charles and Jeremiah Dixon, “The Journal of Charles Mason and Jeremiah Dixon” , transcribed by A. Hughlett Mason (American Philosophical Society, 1969); Danson, Edwin “Drawing the Line: How Mason and Dixon Surveyed the Most Famous Border in America” (John Wiley & Sons, 2001); Wikipedia articles “Mason-Dixon line” at (
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visit link) ; Mackenzie, John “A brief history of the Mason-Dixon survey line” (University of Delaware, 2002 (?)) at (
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visit link) ; Scharf, J. Thomas, History of Delaware, 1609 – 1888, Chapter XI, “Boundary Disputes and Settlement”, (L.J. Richards, 1888) at (
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Also, the “State Boundaries” section of the Delaware Geological Survey (DGS) website at (
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