The Transpeninsular Line

by Dana Kester-McCabe

The story of the Transpeninsular Line goes back several centuries and it is a somewhat twisted tale in which bad maps led to bad blood.

The Transpeninsular Line begins in Mardela Springs and ends in Fenwick Island. The story of this landmark goes back to the dispute between the Calvert and Penn families which eventually led to the boundaries that now make up Pennsylvania, Maryland, and Delaware. It all began when two different British kings paid their debts with land in the American colonies to two different aristocrats: Cecilius Calvert and William Penn. Calvert had the earlier claim with his gift from King Charles II. But the paperwork and relevant surveying calculations were not accurate. Penn's gift came later from King Charles brother the Duke of York who gave away more than what was actually available. When he became King James II, this became a moot point - for a time.

The Penn and Calvert families squabbled about all this back in England without much actual knowledge of the land itself across the ocean. Colonists here were left to deal with the confusing consequences which led to Cresap's War where settlers along the Susquehanna River literally battled for their property rights.

When the British government realized that all this confusion was preventing them from collecting taxes in the region they demanded that the Penn's and Calverts work out an agreement in 1724. This did not last long and in 1732 the two families were forced back to the bargaining table agreeing that the lower three counties of Pennsylvania, now known as Delaware's New Castle, Kent, and Sussex counties, would belong to the Penns. Everything west and south of the 40º latitude line down to Virginia, would remain the property of the Calverts.

Things remained somewhat disputed here on Delmarva until in 1750 surveyors from both Maryland and Pennsylvania were jointly commissioned to establish the boundary between the two colonies and prevent further confusion. But again bad maps and surveying practices got in the way and led to the Calverts losing a bit more land to the Penns. The dividing line was to be drawn from where 40º latitude intersected a twelve mile circle around the city of New Castle, proceeding southward through the center of the peninsula. The border was then supposed to take a turn 90 º traveling due east to Cape Henlopen.

Present day Cape Henlopen was then also referred to as Cape Cornielius. Apparently the location of Cape Henlopen had also been a bone of contention between the two families. The surveyors arrived at what they believed to be the agreed upon cape in present day Fenwick Island, and began their work on the Transpeninusular Line. Though it is the eastern most point along the Atlantic coast in this region it actually does not represent a marked enough change in the coastline to qualify as a cape. The surveyors found a stake on the beach which they presumed to be a land marker and used it as their starting point. Historians now think it was simply a fisherman's tie off stake. Traveling westerly, headed for the Chesapeake, the surveyors reached it completing their task on June 12, 1751.

Permanent stone markers were supposed to be laid down every five miles for twenty five miles ending at the midpoint of the peninsula. The crest of each family engraved on either side indicating whose land was on which side. Unfortunately their path went right through the swampy headwaters of the Pocomoke River where there were not many practical places to lay the stone markers. There are markers just not every five miles. Though the eventual Delaware border is a straight line, the surveyors meandered along what is now Delaware Route 54.

When Charles Mason and Jeremiah Dixon completed their famous survey in 1761 they were given the job of confirming the connecting border northward from the Transpeninsular Line to the twelve mile circle centered on the city of New Castle and creating Maryland's northern border. British King George III ratified the resulting Mason Dixon Line separating Maryland, Pennsylvania and Delaware in 1769.

Today, you can see a Transpeninsular Line marker on the north side of Route 54 east of Mardela Springs at Delmarva's approximate midpoint. There is also a marker in Delmar. It is known as the town that is too big for one state because the line dissects the town putting half in the state of Maryland and half in the state of Delaware. It is believed that forest was cut down along the survey line and colonists were encouraged to settle along it in order to help enforce the Penn-Calvert agreement. There is no clear reason why Delmar inhabitants failed to choose one side or the other.

Another marker is near the state border in Selbyville on Route 113 near Pomeroy's which was known as one of the oldest taverns in Delaware, but sadly burned down recently. Finally there is a marker in Fenwick Island at the foot of the town's lighthouse which was built in 1859.

If we can learn anything from history it is that borders are not necessarily reliable and sometimes cause more problems than they fix. They are in many ways imaginary and therefore no guarantee of anything. On the up side, though there have been conflicts from time to time, since we gained independence it has been the open borders between our states which have provided an environment where commerce and good will can thrive. Proving once again that when we focus less on what divides us we find ourselves uniting.


Drawing the Line: How Mason and Dixon Surveyed the Most Famous Border in America
By Edwin Danson
John Wiley & Sons, Inc. New York

Edge Effects: The Border-name Places
By Robert D. Temple
iUniverse, Inc. New York


Worcester County, Maryland's Arcadia
By Reginald Van Truitt, Millard G. Les Callette - Worcester County Historical Society - 1977

Historical Marker Database

The Pennsylvania Magazine of History and Biography, Volume 38