Power, pride and control of the resources of the new land in America are what formed the borders of Delaware, Pennsylvania and Maryland, not the region's natural resources or latitude and longitude lines. Controlling this newly discovered part of the world was an economic necessity. It was all about increasing one's power, wealth, and even pride.

The dispute over the lands between the Penns, the Calverts and Lord Baltimore, and the Duke of York from the King of England's land grants are what ultimately formed the boundaries of Maryland, Pennsylvania and Delaware. The land grants occurred in the the late 1600s, and the final survey that settled the dispute began in the fall of 1763.

The bickering between the entities lasted many generations. Settlers around the areas that are now Wedgewood Road (Delaware), Elbow Lane, Arc Corner Road, and Strickersville Road (Pennsylvania) and Appleton Road and Telegraph Road (Maryland) weren't exactly sure if they were residents of Pennsylvania, the Lower Three Counties (now Delaware) or Maryland.

Most had loyalties to one of the bickering parties. Many of the  original settlers died before they knew if they were residents of Maryland, Delaware or Pennsylvania. Some families living in the unresolved territories accepted the same land grants from both the Penns and Lord Baltimore, solidifying their claims on their lands.

To settle the dispute, more than 80 years after the original land grants, and after much back and forth in the courts of England, the parties agreed to a survey. Highlights of the agreement specified that the Maryland and Pennsylvania north/south border would be latitude line 15 miles south of the then-southernmost point in Philadelphia (now 30 South Street, near Second Street). The east-west division would be the a line north (the tangent) from the center of the lower peninsula. The Duke of York's lands would include a northern boundary with a 12-mile arc from the center of New Castle.

Local surveyors began by marking the tangent and surveying the 12-mile arc. Progress was slow and the parties involved did not trust the measurements of the local surveyors. After a meeting in England, a new team, led by Charles Mason and Jeremiah Dixon, was dispatched. Mason and Dixon arrived in Philadelphia in November of 1763 with all the latest surveying equipment of the time. First, they determined Philadelphia’s southernmost point.

To accomplish their survey, the team cut a nine-foot swath, called a visto, across the landscape. When they came upon swamps, rivers, and other large bodies of water, they used triangulations to continue an accurate survey line. The actual survey would take four years to complete, but even longer to be accepted by all parties.

In the spring of 1764, Mason and Dixon crossed the Delaware River and from Stargazer’s Road (near Embreeville), set the Stargazer Stone, a reference stone on the same latitude as the southernmost tip of Philadelphia. They surveyed 15 miles south and determined the border between Pennsylvania and Maryland to be at the 39°43’ parallel.

From there, the team headed south to Fenwick Island and remeasured the tangent line of the Maryland and Delaware border. The original team had correctly surveyed this, and the line barely changed.

In the spring of 1765, Mason and Dixon arrived in the now tri-state area and found the intersection of the 39°43’ parallel and the 12-mile radius; the Arc Corner Monument stands at this location, just off Hopkins Bridge Road, in Delaware.

They continued the survey westward along the 39°43’ parallel. A marker was set at the point where the  tangent line  (separating Maryland and Delaware) met the 39°43’ parallel line (Pennsylvania's southern border and Maryland's northern border), determining the point where the Lower Counties, Pennsylvania, and Maryland met. At this tri-state point, a marker was placed.

The survey continued westward, along the 39°43’ parallel line, until the team's forward progress was stopped by threatening Indians. They were 244 miles from the Delaware River, and just 36 miles short of their goal.

One problem was unveiled with the terms of the survey. There were two slices of land, a wedge and a horn, that were outside of the 12-mile arc and south of the 39°43’ parallel. At first, both slices of land were assigned to Pennsylvania. Eventually, the triangular wedge was ceded by Pennsylvania and was accepted by Delaware in 1921. The horn remained part of Pennsylvania.

Mason and Dixon did not survey the actual 12-mile arc. This was done by the earlier survey team, which placed blazes on trees. Stones were later placed along the approximate border. These stones still remain on some properties along the border, but these stones are not Mason-Dixon line stones.

Stone markers carved with “M” on one side and “P” on the other side arrived from England, as were crownstone markers with Calvert and Penn coats of arms on opposite sides. In 1766, once final survey points were made, the stone markers were placed at one-mile intervals. The crownstones were placed every five miles. Many of the markers still exist, though some are in deteriorating condition.

Extensive information about the Mason Dixon Line can be found at the Mason Dixon Line Preservation Partnership's website: (www.mdlpp.org). Resources used for this story include:  A brief history of the Mason-Dixon survey line by John Mackenzie, College of Agriculture & Natural Resources University of Delaware, Wikipedia, and The History of Mason and Dixon's Line; Contained in an address, delivered by John H. B. Latrobe, of Maryland, before The Historical Society of Pennsylvania, November 8, 1854.