Cresap's War (also known as the Conojocular War) was a border conflict between Pennsylvania and Maryland, fought in the 1730s. Hostilities erupted in 1730 with a series of violent incidents prompted by disputes over property rights and law enforcement, and escalated through the first half of the decade, culminating in the deployment of military forces by Maryland in 1736 and by Pennsylvania in 1737. The armed phase of the conflict ended in May 1738 with the intervention of King George II, who compelled the negotiation of a cease-fire. A final settlement was not achieved until 1767, when the Mason-Dixon Line was recognized as the permanent boundary between the two colonies.
Because the fortieth parallel lay north of the city of Philadelphia, Maryland pressed its claim most seriously in the sparsely inhabited lands west of the Susquehanna River. By the late 1710s, rumors had begun to reach the Pennsylvania Assembly that Maryland was planning to establish settlements in the disputed area near the river. In response, Pennsylvania attempted to bolster its claim to the territory by organizing a proprietorial manor along the Codorus Creek, just west of the river, in 1722. This action prompted a crisis in relations between the two colonies, leading to a royal proclamation in 1724 which prohibited both colonies from establishing new settlements in the area until a boundary had been surveyed. However, the two sides failed to reach agreement on the location of the boundary, and unauthorized settlement recommenced within a short time.
In 1726, John Wright opened a ferry service across the Susquehanna, greatly easing transportation between the disputed area and Lancaster County, Pennsylvania. By 1730, a number of Pennsylvania Dutch settlers had crossed the river and taken up residence. Determined to counter this development, a Marylander, Thomas Cresap, opened a second ferry service at Blue Rock, about four miles (6 km) south of Wright's Ferry.
Owing to the royal proclamation of 1724, the Pennsylvania settlers did not have clear title to the lands that they occupied. Apparently in defiance of the proclamation, Maryland granted Cresap title to five hundred acres along the west bank of the river, much of which was already inhabited. Cresap began to act as a land agent, persuading many Pennsylvania Dutch to purchase their farms from him, thus obtaining title under Maryland law, and began collecting quit-rents (an early form of property tax) for Maryland. In response, Pennsylvania authorities at Wright's Ferry began to issue "tickets" to new settlers which, while not granting immediate title, promised to award title as soon as the area was officially opened to settlement.
Sometime in late October, 1730, Cresap was attacked on his ferry boat by two Pennsylvanians. According to Cresap's Maryland deposition, Cresap and one of his workmen were hailed by the Pennsylvanians and began rowing the two men from the east to the west. Sixty yards into the trip, the Pennsylvanians turned their guns on the Marylanders and a fight ensued with Cresap attempting to use the oars to defend himself. After a short struggle, both Marylanders ended up in the water, holding on to the boat to keep from drowning. The Pennsylvanians tried to force Cresap to let go of the boat, and when Cresap asked if they intended to murder him, one swore that he did. Cresap eventually escaped when the boat drifted to shallow water near a large rock where Cresap was stranded for several hours until rescued by a friendly Indian.
It would become clear in later testimony that the target of the attack was actually Cresap's workman who was wanted by a Lancaster county landowner for reasons not entirely clear (possibly debts). This workman was captured by the Pennsylvanians and carried forcibly away.
Cresap was dissatisfied by the response of the Pennsylvania magistrate to whom he reported the attack. Although the magistrate eventually signed warrants that brought the two Pennsylvanians to court, he first stated that "he knew no reason he (Cresap) had to expect any justice there, since he was a liver in Maryland."; a statement that the Governor of Maryland would later key on in a letter to the Governor of Pennsylvania. Significantly, Cresap filed charges with Maryland authorities, claiming that Pennsylvania officials had conspired with the attackers and with local native tribes to drive him from the area., From this point onward, Cresap would maintain that as a resident of Maryland, he was not bound by Pennsylvania law and was not obliged to cooperate with Pennsylvania's law enforcement officers.
Cresap first obtained a patent from Maryland for a ferry at Peach Bottom, near the Patterson farm, then shot several of Patterson's horses. One of the Marylanders, Lowe, was arrested and jailed, but the other Marylanders broke into the jail and freed him.
Cresap then obtained one for "Blue Rock Ferry" and several hundred acres of land, about 3½ miles south of Wrightsville, forcibly took possession of John Hendricks' plantation at Wrightsville.
Cresap was no Quaker by any means; he had previously "cleft" an assailant in Virginia with a broad-ax when clearing disputed land there.
Lord Baltimore had been unwilling to entreat with Indians for what he took, but in 1733, reached an accommodation with the Pennsylvanians, but by 1734, Cresap was again evicting settlers from their Lancaster and York county homes, rewarding his gang members with the properties.
The sheriff of Lancaster County brought a posse to arrest Cresap, but when deputy Knowles Daunt was at the door, Cresap fired through it, wounding Daunt. The sheriff asked Mrs. Cresap for a candle, so that they could see to tend to Daunt's wounds, but Mrs. Cresap refused, "crying out that not only was she glad he had been hit, she would have preferred the wound had been to his heart." When Daunt died, Pennsylvania Governor Gordon demanded that Maryland arrest Cresap for murder. Governor Ogle of Maryland responded by naming Cresap a captain in the Maryland militia.
Cresap continued his raids, destroying barns and livestock, until Sheriff Samuel Smith raised a posse of 24 armed "non-Quakers" to arrest him on November 25, 1736. Unable to get him to surrender, they set his cabin on fire, and when he made a run for the river, they were upon him before he could launch a boat. He shoved one of his captors overboard, and cried, "Cresap's getting away", and the other deputies pummeled their peer with oars until the ruse was discovered. Removed to Lancaster, a blacksmith was fetched to put him in steel manacles, but Cresap knocked the blacksmith down in one blow. Once constrained in steel, he was hauled off to Philadelphia, and paraded through the streets before being imprisoned. His spirit unbroken, he announced, "Damn it, this is one of the prettiest towns in Maryland!"
Following Cresap's arrest, Maryland sent a petition to King George II requesting that he intervene to restore order pending the outcome of the Chancery suit. On August 18, 1737, the king issued a proclamation instructing the governments of both colonies to cease hostilities. Sporadic violence continued, prompting both sides to petition the king for further intervention. In response, the royal Committee for Plantation Affairs organized direct negotiations between the two colonies, which resulted in the signing of a peace agreement in London on May 25, 1738. This agreement provided for an exchange of prisoners and the drawing of a provisional boundary fifteen miles south of the city of Philadelphia. Each side agreed to respect the other's authority to conduct law enforcement and grant title to land on its own side of this boundary, pending the final action of the Chancery Court.
Because Blue Rock Ferry lay well to the north of the provisional boundary, Cresap did not return to the area following his release in the prisoner exchange. In 1750, the Chancery Court upheld the validity of the 1732 agreement, which became the basis on which Charles Mason and Jeremiah Dixon surveyed the modern boundary between Pennsylvania and Maryland in 1767. Today the conflict area is part of York County, Pennsylvania.