Mason and Dixon first established the north/south line dividing Delaware from Maryland. Then the northern boundary Arc separating Delaware from Pennsylvania. Following a brutal winter, the westward line was begun in 1765. They worked their way through this area in April of that year.
Enlisting the help of local surveyors and laborers, they clear a 24-30 ft. wide path through the terrain to facilitate the use of the 66 ft. long Gunter Chain. To calculate an accurate degree of Latitude they used state of the art equipment including a Zenith Sector telescope, astrolabe and transits.
A local Cecil County surveyor, Samuel Maffitt, who is buried in the Old Stone Cemetery was part of the crew.