A Colonial Conflict That Resulted in the Maryland-Pennsylvania Border

In ‘This Week in History,’ a royal geographical error in the colonies leads to a border war that ultimately results in the famous Mason-Dixon Line.

Mason-Dixon Line on U.S. Route 11 between Hagerstown, Md. and Greencastle, Pa. Photo by T.W. Kines, August 1949. Public Domain

George Calvert, Lord Baltimore, requested a charter to begin a colony in the New World. The request was approved by King Charles I in 1632. There is no doubt that Calvert would have been pleased at the news of the approval had he still been alive. Ironically, he died the same year the charter was approved.

The charter, which established the colony’s boundaries between the Atlantic Ocean and Chesapeake Bay with the 40th parallel as its northern border, therefore, went to his eldest son, Cecil, Second Lord Baltimore.

The 26-year-old was now in charge of establishing and governing the Province of Maryland, named after the king’s wife, Queen Henrietta Maria. One of the governing principles for the new colony was the freedom of religion—at least between Catholics and Protestants. It was a reflection of the Protestant king’s marriage to a Catholic princess.

Trouble in England, however, would prove trouble in the colony. Twice, Calvert lost control of the colony for short periods of time due to the outbreak of civil war at home. Nonetheless, he maintained the colony until his death in 1675. The colony remained under the governorship of the Calverts.

A portrait of Cecil Calvert, 2nd Lord Baltimore, with his grandson. Calvert's right hand is holding a map of Maryland that he first published in 1635 to promote his colonization plan. Public Domain

Six years after Cecil Calvert’s death, William Penn received his charter for 45,000 square miles for his colony, Pennsylvania. In similar fashion, his charter was provided by the king, now Charles II, who had owed Penn’s father a substantial debt. Pennsylvania was established as a beacon of religious freedom, a safe haven specifically for the persecuted Quakers, a Christian sect to which Penn belonged. Construction for the city of Philadelphia began almost immediately.

The two colonies of Maryland and Pennsylvania were established to help alleviate religious tensions that often led to bloodshed. Their geographical situations, however, created a different, but just as deadly type of tension: border disputes.

Where Is the 40th Parallel ?

Penn’s charter created a confusing territorial map, labeling the southern border as “a circle drawne at twelve miles, distance from New Castle [in Delaware] Northwards, and Westwards unto the beginning of the fortieth degree of Northern Latitude, and then by a straight line Westwards, to the limit of Longitude abovemenconed [sic].” Placing the southern border along the 40th parallel shouldn’t have been a problem, as that would have butted it up against Maryland’s northern border. The problem was that the 40th parallel for Pennsylvania was based on outdated and inaccurate maps. Instead of being built above the 40th parallel, Philadelphia was being constructed under it (39.9526 degrees north to be exact), and in Maryland territory.

A map showing the Maryland and Pennsylvania claims for their northern and southern borders, respectively. Karl Musser/CC BY-SA 3.0

The incidental overlapping resulted in a bloody eight-year conflict between Marylanders and Pennsylvanians, ultimately forcing the king to get personally involved.

Marylanders contended that the Susquehanna River was Pennsylvania’s southwest border, while Pennsylvanians contended that their border, as stated in the charter, was the 40th parallel—though along a nonexistent version of the specific parallel. Several boundary agreements were made and broken almost as quickly. Another agreement was made around 1717 that established a boundary similar to today’s. That agreement was soon abandoned, and Marylanders and Pennsylvanians continued their dispute to the point of bloodshed.

Encroaching Cresap

Thomas Cresap was born in 1694 in Yorkshire, England. He immigrated to Maryland as a young man. He married Hannah Johnson of Baltimore County in 1727, ultimately settling near her family along the Susquehanna River. Hired as a land agent by Fifth Lord Baltimore, Cresap acquired 150 acres. He and his family moved in 1730 to the river’s west shore. He began his ferry business called Blue Rock Ferry. It seems Cresap, under the direction of Lord Baltimore, began the ferry service to compete directly with the Pennsylvanian John Wright.

Wright had begun Wright’s Ferry shortly before Cresap’s arrival. The direct competition was not the only aspect of Cresap’s move that ruffled Pennsylvanian feathers; it was the fact that Cresap was doing so in lands claimed by Pennsylvania, as records showed he was conducting business four miles north of the actual 40th parallel.

Cresap, who by now had acquired a reputation as a frontiersman, an Indian trader, and all-around ruffian, was fully aware of the border dispute and his current place in it. He had earned his nickname as the “Maryland Monster” by Pennsylvanians. In 1731, his mere presence was enough to have him attacked.

Three shots were fired across the Susquehanna, though not at him, but signaling that a party on the other side needed a ride. He and his ferry worker rowed over to ferry three men across the river. As they made their way across, the men grabbed his worker, pushed Cresap into the river (presumably hoping he would drown), and rowed back over to their original side, retaining Cresap’s flatboat and worker.

Cresap survived and presented before a judge in Pennsylvania’s Lancaster County, requesting a warrant to arrest the men. The judge demurred, telling Cresap that ultimately he had no right to be ferrying in his current location. It was only one of Cresap’s many clashes with locals and local authorities over the next five years.

‘Root Out the ... Villains’

Samuel Blunston was a land surveyor for Lancaster County and a good friend of Wright. He was commissioned to survey areas that would later become Northern York, Cumberland, and Franklin Counties. Having conducted these surveys in 1732 and 1733, he returned to create a pre-warrant system for future Pennsylvania settlers. Blunston, too, was caught in the middle of this border dispute along the Susquehanna, leading him to surmise, “It is a question now whether we shall give up that side of the river to them or defend against them. And if that side were given up, it would seriously affect the inhabitants on this side, where there are already too many malcontents. ... We should root out the nest of villains.”

Blunston recommended a defense of the border, especially at Wright’s house, which he noted as the area’s “only garrison.” There had already been a bloody skirmish in Wright’s wheat field. Another would take place in 1735.

In January 1734, the sheriff of Lancaster attempted to arrest several of Cresap’s tenants, but Cresap fired at the sheriff’s men, leaving one wounded. A second attempt was made to arrest Cresap that same month with similar results (though according to a deposition by John Ross, of Lancaster County, a man wounded in the leg during this second attempt ultimately died).

Cresap’s Arrest

In September 1736, hundreds of Marylanders and Pennsylvanians formed companies, threatening a battle. At one point, some of the Maryland soldiers broke into the homes of their adversaries and robbed them. A battle, however, never commenced.

In November 1736, the border dispute earned the name Cresap’s War. Pennsylvanians accused Cresap of murder. It was enough of a charge to garner a company of 24 armed men, led by the sheriff of Lancaster County, to march onto Cresap’s property, surround his house, and demand his surrender.

Cresap, with his family and several others inside, resisted the call to surrender. The Pennsylvanians decided to take it a leap further—they set the house on fire. The inhabitants fled the house, though not safely, as several were wounded and one killed by the firing Lancaster men. Cresap was arrested and hauled to prison in Philadelphia. Exemplifying his defiant and ruffian attitude, Cresap looked around the city and comically stated, “This is one of the prettiest towns in Maryland.”

Order of the King

The attack on Cresap’s home was enough to force King George II to intervene. The Maryland Council received the king’s command “that the Governors of the respective Provinces of Maryland & Pensylvania for the time being Do not upon pain of incurring his Majestys highest Displeasure permit or Suffer any Tumults, Riots, or other Outrageous Disorders to be Committed on the Borders of their respective Provinces.” King George II ordered the governors of both provinces to desist providing any new land grants until the matter was resolved.

The word of the king was enough. It was during this week in history, on May 25, 1738, that the “Governors of the respective Provinces of Maryland and Pensilvania” agreed that the orders of the king would be obeyed “until the Boundaries shall be finally settled,” officially bringing Cresap’s War (also known as the Conojocular War) to an end.

Illustration of Charles Mason and Jeremiah Dixon surveying the Mason-Dixon line, circa 1763–1768. Public Domain

It was a few years before land negotiations made further headway. These included the 1744 Treaty of Lancaster between Maryland, Pennsylvania, Virginia, and the Iroquois Confederation. In 1763, Charles Mason and Jeremiah Dixon, surveyors hired by the Penn and Calvert families, began their four-year survey. The survey, which established borders between four colonies—Maryland, Pennsylvania, Delaware, and Virginia (now West Virginia), became known as the Mason-Dixon Line.

Cresap served two years in a Philadelphia prison, more for serving as a linchpin during the border conflict than for allegedly committing murder. Released after the peace agreement, he lived until 1790, favored and unfavored by various groups in the colonies. Pennsylvanians despised the “Maryland Monster,” the Native Americans called their trading partner “Big Spoon” in appreciation for always having food readily available, British officers during the French and Indian War held him in low regard, and in Maryland, according to a historical marker established in his honor, “Cresap was honored south of the Mason-Dixon line as the ‘Maryland Frontiersman’ and a ‘Pathfinder-Pioneer-Patriot.’”

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