A piece of African-American history that was once sold for just a few dollars could fetch millions when it goes up for auction later this month. A copy of the Emancipation Proclamation is expected to raise between $1.8 million and $2.4 million when it is sold at the Robert  A. Siegel Auction Galleries in New York City.

While the original Emancipation Proclamation lies intact in the National Archives in Washington, D.C., the document to be auctioned is nonetheless extremely valuable. In 1864, President Abraham Lincoln signed 48 copies that were then sold for $10 each as part of fundraising efforts by the Sanitary Commission, an organization that worked to improve conditions at military camps during the Civil War. The document to be auctioned is just one of twenty-six known surviving copies of the proclamation that declared slaves in states that were considered rebellious “ then, thenceforward, and forever free.”

President Abraham Lincoln’s original signature alone could be worth up to ten thousand dollars, according to  Seth Kaller, who is an expert on American historical documents and represents the private owner of the document that is now up for sale. However, the Emancipation Proclamation’s historical and cultural significance plays a big role in why Kaller believes this copy could fetch a multi-million dollar price tag. “It’s all about the content. Once you’re told the story, it’s infused with significance and it becomes something people really relate to,” says Kaller.

Kaller also notes that the opening of the Smithsonian National Museum of African American History and Culture, which is scheduled for 2015, could bring even more demand for documents similar to this copy of the Emancipation Proclamation. “The creation of the new African-American museum is creating interest in some new collectors and it’s a trend that’s likely to continue,” he explains.

The document’s auction will come just days after African-Americans across the country commemorate slavery’s abolition in celebrations on June 19, or Juneteenth. While the original Emancipation Proclamation was issued on January 1, 1863, it only outlawed slavery in certain parts of the country. It was not until later that actual freedom extended to slaves in places like Texas, which recognizes its emancipation day as June 19th, 1865. This event is considered the source of the Juneteenth celebrations that endure today.

Individuals hoping to score the rare copy of the Emancipation Proclamation will begin bidding in person, via the phone and over the Internet on June 26 at 1:30 PM.

“This document that Lincoln signed changed the world. One way to give history authenticity is by looking at these kinds of documents,” Kaller says.

Amara Omeokwe is a TV Producer at CNBC. Follow Amara on Twitter at @ProducerAmara.