Often associated with the Civil War, the Mason-Dixon Line was actually surveyed a century before the war to end a border dispute between Pennsylvania and Maryland.

PHILADELPHIA — If Todd Babcock had his way, the Mason-Dixon Line would be known as the technological marvel that kept Philadelphia in Pennsylvania, not as flawed shorthand for the Civil War divide between North and South.

The land survey that settled a border feud between Pennsylvania and Maryland predates the Civil War by a century. It started at a house in Philadelphia whose location was only recently confirmed by a group of college students paging through centuries-old property records.

The research led state officials to approve a historical marker for the site last month. Babcock and other members of the volunteer Mason and Dixon Line Preservation Partnership plan to erect it for the line’s 250th anniversary in 2013.

“Charles Mason and Jeremiah Dixon’s accomplishment has been buried in the fog of bad history and I hope to change that,” said Babcock, 46, a professional surveyor from Fleetwood, Pa.

Babcock’s efforts come as the U.S. marks the 150th anniversary of the Civil War. “Mason-Dixon” has become synonymous with the North-South line — Maryland allowed slaves, Pennsylvania did not — even though Maryland was a Union state.

The boundary had nothing to do with that. Begun in 1763 and lasting four grueling years, the demarcation involved celestial navigation of more than 300 miles of wilderness while transporting a delicate 6-foot-long telescope, food and other supplies by horseback, said Babcock.

Mason and Dixon were British surveyors hired to settle a dispute between two powerful families: the Penns of Pennsylvania and the Calverts of Maryland. The Calverts claimed land extending north to Philadelphia.

Mason and Dixon were charged with marking the border at a latitude 15 miles south of Philadelphia. But what was the city’s southernmost point?

Municipal records from that time indicate only that the point was the northern wall of a house owned by Joseph Huddle. Babcock said researchers long surmised the house was near Front and South streets — now an area with funky shops and restaurants — but no one had found a deed with Huddle’s name and a location.

Enter Janine Black. The Philadelphia resident had contacted Babcock’s group after reading that Huddle’s house supposedly stood a few blocks from her home. In a city teeming with historical markers, she asked, why was there none for this house?

Babcock told her of the missing documentation. So Black obtained a small grant for students to comb city archives.