The Conojocular War - the best known of these flare-ups - pitted the cantankerous Thomas Cresap (c.1702–c.1790) against his neighbors and local law enforcement. The ongoing boundary dispute led to frequent and often violent confrontations on the frontier. During that time both proprietors died, bequeathing the controversy to their heirs. Neither Penn nor Calvert liked the Board of Trade’s decision and the dispute remained unresolved for nearly 50 years. In 1735 this map was used as an exhibit in the case of the Penns against Calvert to settle the Pennsylvania–Maryland boundary dispute. (Initially governed as one colony, Pennsylvania and the Lower Counties established separate legislatures by 1704, but shared a colonial governor until the American Revolution.) In 1685, after further negotiations had failed, the Board of Trade and Plantations in London set the boundary between Pennsylvania and Maryland at 40 degrees latitude north, extended westward to the Indian lands. Penn’s control of this territory, to which Calvert also had a claim, gave his Pennsylvania colony much needed access to the sea. That same year Penn further aggravated Calvert when he leased the “Lower Counties on the Delaware” from the Duke of York. At issue was as much as 4,000 square miles of territory. The two proprietors next met face-to-face in Annapolis in December 1682 and again failed to reach an understanding. In August 1681 he sent a cousin to the Patuxent River estate of Charles Calvert (1637–1715), Third Lord Baltimore, on an unsuccessful mission to settle the matter. Penn almost immediately recognized the need to establish a clear demarcation between his holdings and those of the Calvert family. to the beginning of the fortieth degree” of latitude and as far west as 5 degrees longitude from the Delaware River. Pennsylvania - literally “Penn’s woods,” a name chosen by the king that the proprietor unsuccessfully sought to reject -stretched south from the 43rd parallel to a “Circle drawne at twelve miles distance from Newcastle. In 1681 he convinced King Charles II to satisfy the crown’s debt of ₤16,000 to his father with one of history’s largest individual land grants. Like Calvert, the Quaker William Penn (1644–1718) envisioned a New World settlement characterized by religious freedom. Their economic fortunes now bound to the English market, Maryland planters soon emulated their southern neighbors in Virginia by importing African slaves to work their fields beginning in 1642.

Calvert’s North American outpost quickly embraced tobacco as its primary cash crop.

Granted land stretching from the southern bank of the Potomac River to a “point which lieth under the Fortieth degree of north latitude,” Calvert named his colony Maryland to honor the king’s French consort, Henrietta Maria. In June 1632 Britain’s King Charles I awarded Cecil Calvert (1605–75), Second Lord Baltimore and a devout Catholic, a charter for a proprietorship in North America. The closest connection for 21st-century Americans may be “Sailing to Philadelphia,” singer and guitarist Mark Knopfler’s 2000 ode to “stargazer” Charlie Mason and “Geordie boy” Jeremiah Dixon, who are “Sailing to Philadelphia / To draw the line / A Mason-Dixon Line.” But during the 18th and 19th centuries, the creation and existence of the line was of profound importance.īoth Maryland and Pennsylvania owe their foundation in part to the search for religious tolerance. Today, the Mason-Dixon Line has lost much of its historic significance. For millions living in Antebellum America, Pennsylvania’s southern boundary represented a political as well as a psychological demarcation between freedom and enslavement, between North and South. Within 75 years of its completion to resolve an eight-decade-long dispute between two colonial proprietors, a boundary line drawn in the 1760s by two English scientists had become a symbol of the growing rift in the young nation. Such was the power of the Mason-Dixon Line. “When I found I had crossed that line,” recalled Harriet Tubman, “I looked at my hands to see if I was the same person.

Mason dixon line