Someone has stolen the Mason-Dixon Line!

Image-Google Search-Mason-Dixon Line
Did Someone Steal The Masey-Dixy Line?

The Mason-Dixon Line

Well, I guess it’s not quite as bad as all that. No one has actually taken our southern border. And that boundary is not really part of the original Mason-Dixon Line, anyway.

The Mason-Dixon Line defined the southern boundary of Pennsylvania with West Virginia, Maryland, and Delaware, and the western boundary of Delaware with Maryland. The actual survey line between Maryland and Delaware has also been referred to as the North-South Boundary.

So, am I in Somerset County or Sussex County?

Relax! You will still pay your taxes in Sussex and Delaware this year.…although that was heavily disputed and violence was at least threatened on more than one occasion, in the late-1700s, when tax collectors from Somerset County, Maryland, continued to harass citizens of present day-Sussex County. The disputed territory laid south of a line, that ran from the Atlantic Coast, along the southern edge of the Indian River up to Millsboro, through Georgetown, and over to Greenwood.

The problem stemmed from disputes over honoring the 40th parallel, the previously agreed upon boundary line between Calvert’s Maryland colony and Penn’s Delaware counties. The situation was further complicated because attempts to transfer coastal landmarks from navigation maps onto land survey maps resulted in differences of some 25 miles as to where “Cape Hinlopen” actually was. Cape Henlopen was thought to be where Fenwick Island now is because of a bulge in the mapmaker’s depiction of the shoreline that mariners identified as the cape.

Oh, for the want of a decent Garmin!

For some 50-years, settlers in southern Sussex County could go to bed in Delaware and wake up in Maryland, and vice versa, depending upon who had the upper hand.

Finally, in May 1750, Lord Hardwicke, at the behest of the commissioners of the provinces of Maryland and Pennsylvania, issued a decree, and the Colonial Survey of 1751 was begun. The resulting  boundary between southern Delaware and Maryland would be known as the Transpeninsular Line . Unfortunately, the survey was halted due to the death of Lord Baltimore and not until over a decade later was it concluded by the storied Mason & Dixon, in 1768, when a double crownstone was set at Middle Point.

The Transpeninsular Line was resurveyed in 1974, by Delaware and Maryland, and the restoration of the historical monuments and agreements between our two states for their maintenance were also accomplished at that time.

Preserving the Heart and Soul of Delmarva

If your family has been part of the Sussex County fabric for a long time, or if you just love the area and its history, you may be interested in something that I only recently discovered myself: the Edward H. Nabb Research Center for Delmarva History & Culture, located on the campus of Salisbury University.

Now that you know a little more about the land disputes between our long-ago heads of government, you have an opportunity to understand how this impacted our people and our culture. Join the families of Sussex and Somerset in what must surely be a wonderful arena for sharing knowledge and history, and will most certainly become an enjoyable learning experience for first-timers.

Families of Old Somerset: Maryland’s Lost Territory–Sussex County

Panel Discussion, Nabb Research Center

Saturday, July 16 1 p.m.

Join us in the third of a series of round table discussions about the early families of Old Somerset County, Maryland. Focusing on the territory now part of Sussex County, Delaware, this discussion will be led by local family historians who have valuable insights about the early families.



  • Report on Surveys of Delaware-Maryland Boundaries, Buford K. Meade, 1982
  • Fenwick Island Boundary Stone, Michael Morgan (The Wave)