The Mason-Dixon Map the Library of Congress Tried to Buy Returns to Auction

The original 1768 manuscript survey, once purchased by Malcolm Forbes for a world-record price, will be offered by Brunk Auctions Oct. 29 during America's 250th anniversary year

ASHEVILLE, N.C., Oct. 15, 2026 /PRNewswire/ -- In April 1982, the Library of Congress went to Christie's in New York hoping to acquire one of the most consequential maps in American history. It did not get it.

The original hand-drawn manuscript survey of the Mason-Dixon Line instead sold for $360,000 to Malcolm Forbes, then president of Forbes magazine. Contemporary coverage in The Washington Post called the result a "world record price for an autographed map." At the same sale, a broadside of the Declaration of Independence sold for $285,000, $75,000 less than the Mason-Dixon manuscript.

"This is one of the most important documents in American history," Forbes told The Washington Post after buying it in 1982. "I plan to loan it to Princeton University, which owns the other third of the map."

On October 29, the map returns to auction at Brunk Auctions in Asheville, North Carolina, during the nation's 250th anniversary.

Surveyors Charles Mason and Jeremiah Dixon prepared the manuscript in Philadelphia between December 1767 and February 1768 after years spent resolving a nearly century-old boundary dispute between the Penn and Calvert families over the dividing line between Pennsylvania and Maryland. The nearly 76-inch-long manuscript consists of six joined sheets of laid paper, finely drawn in pen and brush over pencil and signed "Cha: Mason" and "Jere: Dixon" beneath an ornamental cartouche.

The work required Mason and Dixon to cross rugged wilderness and the Allegheny Mountains with the aid of Indigenous guides, hunters, guards and axemen. In September 1767, 26 Indigenous axemen refused to proceed beyond the Monongahela out of fear of the Shawnees and Delawares. The final 36 miles of the western boundary therefore remained unsurveyed until a joint Virginia-Pennsylvania survey completed the line in 1784. In March 1768, Benjamin Chew, the Penn family's representative, led a delegation to Fort Pitt to negotiate a treaty with the Shawnees and Delawares. What began as a colonial property dispute would ultimately assume far greater significance.

More than 50 years later, during the congressional debates surrounding the Missouri Compromise of 1820, the Mason-Dixon survey line was used as part of the cartographic framework designating the divide between slave and free states and territories. Christie's later described the line, quoting historian Laurence Wroth, as "a symbol differentiating two cultures, two definite states of mind which have existed in the nation from the beginning of its settlement."

The manuscript itself nearly disappeared from history.

For generations, the western survey remained among the Chew family papers and was assumed to be an engraving. In January 1963, historian Nicholas Wainwright and Benjamin Chew III were examining the strip when Chew noticed that its cartouche differed from that of the printed version. Comparison with the surviving eastern manuscript at Princeton University confirmed that the western strip was an original manuscript drawing by the same hand.

The Chew family sold the map at Christie's in 1982, where Forbes acquired it for $360,000. The Map Collector subsequently described the result as the highest price ever paid for a map at the time. Two decades later, the manuscript returned to Christie's with an estimate of $800,000 to $1.2 million. It sold in March 2002 for $556,000 to a private collector.

Following that sale, the privately held map underwent extensive conservation at Colonial Williamsburg before being exhibited at the DeWitt Wallace Decorative Arts Museum as part of Degrees of Latitude. Conservators removed the map's deteriorating linen backing, treated stains and damage, repaired tears and losses and relined the document with Japanese paper. The painstaking removal of the old backing alone took more than 200 hours across the map's 76-inch length.

The manuscript remained on view at Colonial Williamsburg through March 2006. Now, more than four decades after the Library of Congress sought to acquire it and nearly 260 years after Mason and Dixon put pen to paper, the map is returning to the auction block.

"Most historical documents of consequence exist in multiples, copies, printings, other surviving drafts. Having the original hand-drawn, manuscript version of such an iconic American map is exceptionally rare. There is no other known original, and in the intervening centuries, the line they drew has become part of the fabric of our culture. Over the years, it has been used in critical developments in our country's history. 'Whistling Dixie' and 'old Dixie' are references that lead back to this 1768 map, and it happens to be the reason we still talk about 'north of the line' and 'south of the line' 250 years later. We're honored to bring it to market in America's semiquincentennial. It is a once-in-a-lifetime opportunity for someone to acquire one of the most important documents in US history," stated Andrew Brunk, CEO and President of Brunk Auctions.

The Mason-Dixon manuscript is expected to draw significant collector interest and will open at $500,000 when it comes to auction October 29 alongside a related group of period maps and manuscripts documenting the survey. The auction will take place at Brunk Auctions, 117 Tunnel Road, Asheville, North Carolina and begins at 10:00 a.m. ET.

For more information, contact Madelia Hickman Ring at 828-254-6846 or [email protected], or visit Brunk Auctions online at www.brunkauctions.com 

Media Contact: Risa B. Hoag | GMGPR | 845-627-3000 | Cell: 914-643-7878 | [email protected]

SOURCE Brunk Auctions