One of only eight surviving ratified copies of the U.S. Constitution discovered in an old filing cabinet in North Carolina soon will be auctioned off to the highest bidder. The starting price is $1 million but it's expected to go for much more than that.

Brunk Auctions, a North Carolina-based auction house, is facilitating the sale of the document, which was found in 2022. 

It is only one of eight known surviving signed ratification copies of the document, according to Brunk Auctions. And the sale, which is set to take place on Sept. 28, is the last and only other recorded sale of a similar document since 1891, the auction house said.

Here's what you need to know.

More about the Constitution and how many copies were made

Only a fraction of the 100 copies of the Constitution were signed by then-Secretary of Congress Charles Thomson. Thomson was tasked with sending the copies to state legislatures in the 13 original colonies after the Confederation Congress met on Sept. 28, 1787.

It is that resolution, along with Thomson’s signature, that makes the present copy an official ratified edition of the Constitution, according to the auction house. The copy of the Constitution will be auctioned on the 237th anniversary of the day Congress passed the ratification resolution. 

“James Madison wrote that the Constitution ‘was nothing more than a draft of a plan, nothing but a dead letter, until life and validity were breathed into it by the voice of the people, speaking through several state conventions,'” auctioneer Andrew Brunk said in a statement.

“This simple-looking version is what started breathing life into the Constitution,” according to Brunk.

'Incredibly rare' copy of the U.S. Constitution found in home

North Carolina homeowners found the “incredibly rare” document inside an old filing cabinet when they were getting the house ready for sale in 2022.

The home, located on a 184-acre plantation in the coastal town of Edenton, was sold to the state so it could be turned into a public historic site, according to Brunk Auctions. The property was bought in 1765 by then-Gov. Samuel Johnston. 

It was purchased by another family in 1865, who lived in the home up until its sale. 

Market decides what Constitution copy is worth today, expert says

Seth Kaller, a historic document expert helping with the auction, said in a statement that the sale presents a unique opportunity to own a “cornerstone of our democracy, particularly at this time in our nation’s history.” 

This isn’t the first time Kaller has participated in the auction of a historical document, working with Sotheby’s in November 2021 to sell a Constitutional Convention print for $43.2 million. That same document sold for $165,000 in 1988. 

But this ratification copy, according to Kaller, is “rarer and arguably more significant.”  

“The consignor gave Brunk the luxury of selling it without reserve, with a starting bid of $1,000,000,” Kaller said. “The market will decide what the Constitution is worth to us today.” 

Members of the public will get a chance to take a sneak peek at the document, which will be on display at Federal Hall National Memorial in New York on from 1 to 4:30 p.m. ET on Friday, Sept. 13.