To settle a border dispute involving Maryland, Pennsylvania, and Delaware in Colonial America, surveyors Charles Mason and Jeremiah Dixon worked from 1763 to 1767 to delineate the borders of Maryland, Delaware, and Pennsylvania.
The dispute had its origins almost a century earlier in the somewhat confusing proprietary grants by King Charles II to Lord Baltimore (Maryland) and William Penn (Pennsylvania).
The Mason–Dixon line was marked by stones every one mile and “crownstones” every five miles, using stone shipped from England. The Maryland side says “(M)” and the Delaware and Pennsylvania sides say “(P).” Crownstones include the two coats of arms. Today, while many of the original stones are missing or buried, many are still visible, resting on public land and protected by iron cages.
In 1784, surveyors David Rittenhouse and Andrew Ellicott their crew completed the survey of the Mason–Dixon line to the southwest corner of Pennsylvania. Click here to read more about Lancaster’s favorite surveyor, Andrew Ellicott. Other surveyors continued west to the Ohio River.
The Mason–Dixon line has been resurveyed three times: in 1849, 1900, and the 1960s.
As many as five stone markers can be found along Lancaster County’s southern border.
Where to find the marker
You can find the marker at the intersection of Grubbs Corner Road and Pilottown Road. Click here for the GPS location.