It’s perhaps the most consequential map in American history. And it could be yours.

The hand-drawn chart of the Mason-Dixon Line that eventually divided the free from the slave states is going up for auction. Remounted on backing made of Japanese rice paper, the document will go on sale Thursday in a livestreamed auction.

“It’s not that often that you can really get this close to something that is so historically important,” said Lauren Brunk, vice president of Brunk Auctions in Asheville, North Carolina. “And it was awe-inspiring, really.”

Brunk estimates it could fetch anywhere from $800,000 to $1.2 million for the anonymous seller.

The survey by Charles Mason and Jeremiah Dixon was originally meant to settle a border dispute between the then-colonies of Maryland and Pennsylvania.

But when it was used in the 1820 Missouri Compromise to establish the limits of human bondage in the still adolescent United States, it became synonymous with the fundamental divisions that exploded into civil war four decades later.

“The Mason-Dixon Line that most Americans know is this dividing line between the northern free states and the southern slaveholding states,” Brunk said. “But the line was not drawn for that reason.”

A popular theory is that the term “Dixie” comes from Dixon, though the true origin is disputed.

Soon after it was drawn, the linen-backed strip of paper — 76 inches (193 centimeters) long and 6.5 inches (16.5 centimeters) tall — was given to the family of attorney Benjamin Chew, who represented the descendants of Pennsylvania founder William Penn.

The map remained in the family’s hands until 1982, when late publisher Malcolm S. Forbes outbid the Library of Congress and bought it for $360,000, Brunk said.

At the time, it was said to have been the highest price ever paid at auction for an American map.

The map changed hands again in 2002. (A vertical section showing the Delaware-Maryland border is housed at Princeton University.)

Brunk reached out to officials at the Library of Congress to see if they wanted to bid on it again.

“I wanted them to be aware that this was coming back to the market,” she said. “And they said, at this point, budgets being what they are, they were just not in a position to buy it.”

But if some patriot out there wants to purchase it on the library’s behalf, Brunk said, “they’d be happy to have it.”