It’s a bloody piece of history.

A small section of a dress bearing a dark blood stain from President Abraham Lincoln will be up for sale later this month when the New York International Antiquarian Book Fair comes to the Park Avenue Armory on April 21.

The macabre artifact has a whopping $125,000 price tag, and is being sold by exhibitor Daniel R. Weinberg, owner of Abraham Lincoln Book Shop in Chicago.

“In my 50 years at [the shop] I’ve handled five blood relics,” Weinberg told The Post, adding that “the book fair occurs a mere six days after the 157th anniversary of the assassination.”

The 1.625-inch by .5-inch swatch was part of a dress worn by famous actress Laura Keene. She was starring in “Our American Cousin” at Ford’s Theatre in Washington DC, where Lincoln was shot by John Wilkes Booth, on April 14, 1865.

“This particular costume fragment, though small, carries a great moment, actually having been at the scene of the crime,” Weinberg said.

And it seems Keene was very much on the scene.

After Booth shot Lincoln, the English-born actress walked up to his box carrying water and, at some point, she cradled his head in her lap as Dr. Charles Leale looked for the bullet. Keene later led the way as the wounded president was carried from the theater to the boardinghouse Petersen House across the street, where he died the next morning.

According to Weinberg, most of the blood artifacts from that night are pieces of towel or pillow coverings from Petersen House and do not have the same deep coloring as the blood that fell onto Keene’s dress.

Accompanying the fabric in the sale is a note from Keene, whose friend asked for the item. It reads: “I accede to your request. Very truly yours / Laura Keene / New York / May 20th, 1865.” The weave and design match a bloody dress swatch that is at the Abraham Lincoln Presidential Library and Museum.

This wouldn’t be the first specks of Lincoln’s vital matter to sell. In 2020, a lock of Lincoln’s hair and a blood-smeared telegram were bought for more than $81,000 by Boston-based RR Auctions. And Weinberg noted that a bloody cuff with much fainter stains sold in 2008 for $93,000 by Heritage Auctions.

But this one is unique. Weinberg said: “The blood is much darker than others, indicating that it was close to the wound.”