The Penns and the Calverts quibbled over boundary line

Have you heard about the family feud between the Penns and the Calverts? It’s an important chapter in American history.

England’s King Charles I awarded the charter for the Pennsylvania province to William Penn in 1632, establishing Pennsylvania’s southern border at the 39th parallel.

The Maryland province proprietor was Cecil Calvert (Lord Baltimore), son of Sir George Calvert. His charter specified that Maryland’s northern border was at the 40th parallel. 

A huge boundary dispute erupted with each colony claiming the “gap” between the parallel lines – a swath of land about 69 miles wide. One major urban center was involved. Which colony “owned” Philadelphia?

 The late Kathryn Devan Kemp, former columnist with The Birmingham (Ala.) News, said: “For a while, Penn and Calvert each tried to convince the inhabitants of the disputed area that they were citizens of their colony and should pay taxes appropriately.” 

“The residents did not necessarily care where they lived, but they did not want to pay taxes to both colonies,” she said. 

“The battle between the Penn and the Calvert families continued for three generations…and the tensions between the two families escalated,” Kemp wrote. In 1750, King George II stepped in to declare a truce that favored the Penns, but no one knew for sure where the boundary line was.” 

Two British scientists named Charles Mason and Jeremiah Dixon were commissioned in 1763 by King George III to travel across the Atlantic Ocean and finalize an agreement between the two colonies. 

Mason was an astronomer who had worked at the Royal Observatory, and Dixon was a well-known surveyor and mathematician. A contract was signed in 1763 by representatives of the Penn and Calvert families.

 

Mason and Dixon determined that the Pennsylvania-Maryland border would be laid 15 miles due south of Philadelphia and extend 233 miles to the west. 

Phil Mawson of BBC News reflected on the significance of what came to be known as the Mason-Dixon Line. 

“It was the equivalent of moon landings,” according to David S. Thaler, a trustee of the Maryland Historical Society in Baltimore and an expert on the Mason-Dixon project. 

“The stakes were very high,” Thaler said. “About 4,000 square miles of territory was in dispute.”

 

David Thaler

The divide between Pennsylvania and Maryland “was the most outstanding scientific and engineering achievement, not only of its day, but of the ‘American Enlightenment,’” Thaler said. 

“It was so advanced for its time. The brains were the best and the technology was the best,” some of the most advanced surveying equipment of the day. 

Todd Babcock of the Mason and Dixon Line Preservation Partnership, based in Athens, Pa., told Mawson: “At the time, all Mason and Dixon had in front of them was wilderness. West of the Susquehanna River and approaching the Allegheny Mountains there were very few roads.” 

The English surveyors were guided by a group of Native Americans from the Iroquois Confederacy…and by the constellations in the night sky. 

“It was all mature forest,” Babcock said, “so that required axe-men to cut down the trees, pack mule drivers to get the trees out of the way as well as cows for milk, chain carriers, instrument bearers and tent bearers. It was like a small army moving through the woods.” 

“They started off with a crew of five, but by the time they got toward the end of the survey, the party had grown to about 115,” Babcock said. 

“I think they thought it would take a year or two, but it ended up taking five.”