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 originated 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 mile and “crownstones” every five miles, using stones shipped from England. The Maryland side says “M,” and the Delaware and Pennsylvania sides say “P.” Crownstones include two coats of arms. Today, while some of the original stones are missing or buried, many are still visible.
Shown below is a “crownstone” boundary monument on the Mason–Dixon line. These markers were originally placed at every fifth mile along the line, ornamented with family coats of arms facing the state they represented. The coat of arms of Maryland’s founding Calvert family is shown. On the other side are the arms of William Penn. Click here to read about where you can find Lancaster County’s only crownstone.
In 1784, surveyors David Rittenhouse and Andrew Ellicott and their crew completed the Mason–Dixon line survey 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 was resurveyed 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.
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You can own beautiful reproduction maps of Fulton Township, where this Mason-Dixon marker is located.
1864 Map of Fulton Township, Lancaster County, PA$24.99 – $25.99
Sehner-Ellicott-von Hess House: Home to the surveyor who helped define America
Today, 123 North Prince Street houses the Historic Preservation Trust of Lancaster County, but in the early 1800s, America’s best and brightest mathematician and surveyor, Andrew Ellicott, lived here. Click the link to learn more.
Side Quest: Briar Patch hunt for Lancaster County’s only Mason-Dixon Line Crownstone
To settle a 1730s border dispute involving Maryland and Pennsylvania, surveyors Charles Mason and Jeremiah Dixon placed 133 stone markers—each weighing more than 400 pounds—to delineate the borders between these states. Lancaster County has five of them. Join me for a scramble through the briar patch as I search for an elusive Mason-Dixon line “crownstone.”
Armchair Explorer: Make your reservation today for the Pequehanna Inn – Pennsylvania’s Crown Jewel answer to Lake Placid
In an alternate universe, a five-story, 384-room luxury hotel sits high on a hill above the town of Pequea with a commanding view of the Susquehanna River. Click here to learn the uncanny history of the failed Pequehanna Inn.