A rare lock of Abraham Lincoln’s hair, removed by surgeons following his 1865 assassination, is expected to draw thousands of dollars when it hits the auction block this Wednesday.

The hair is part of the sprawling Dan Madsen collection, which also features rare Mark Twain first editions and Revolutionary War-era documents.

Heritage Auctions in Dallas will have a host of items up for auction related to both Lincoln and the author Twain. They are part of a collection owned by Madsen, who started in his youth collecting comic books and science fiction items.

“I remember watching the Civil War PBS series by Ken Burns, and what stood out to me was what an amazing man Abraham Lincoln was,” Madsen said. “I started buying books and learning more and more about him and just became fascinated with Lincoln. I started getting auction catalogs, making friends in the Lincoln collecting community. I would look at every auction catalog from the last 40 years that had anything Lincoln. It was almost like a wildfire. Once I started collecting Lincoln items, I just went crazy.”

The fascination with Twain began in a similar manner after Madsen picked up a biography and was captivated by the author’s outsized and lasting impact on American culture. He saw parallels between the two, particularly in how both were proponents of equal rights, and so he began collecting Twain items as well.

Part of the collection is a group of 18 snippets of hair from Lincoln’s head, which initially belonged to Dr. Charles Sabin Taft, the second surgeon to treat Lincoln on the night of his assassination in 1865, according to the lot description at Heritage Auctions. The first surgeon to arrive, Dr. Charles Leale, originally removed the hair to gain access to Lincoln’s head wound. The lock of hair was given to Mary Todd Lincoln, who soon gave it to Taft.

Taft willed the hair to his son. In 1905, Lincoln’s secretary John Hay received six strands, mounting them in a ring presented to Theodore Roosevelt. Additional portions were sold in 1908 and again in 1914 to Henry C. Hines, who preserved them in a sealed container until 1993.

As of Tuesday afternoon, the current bid was $5,750.

Another notable item up for auction is an 1860 campaign flag from Lincoln’s presidential run with vice presidential candidate Hannibal Hamlin. It is most notable for its misspelling of Lincoln’s first name as “Abram.”

There is also an invitation to ride aboard Lincoln’s funeral train and a pass to his April 1865 funeral at the Executive Mansion in Washington, one of fewer than 600 issued to officials and dignitaries.

Among the Twain memorabilia is a terra cotta plaque Twain commissioned depicting himself and author George Washington Cable, as well as a business card bearing Twain’s birth name, Samuel Clemens.

In addition, rare book collectors will find first editions of Twain’s first novel, “The Celebrated Jumping Frog of Calaveras County,” as well as “A Connecticut Yankee in King Arthur’s Court” and “A True Story, and the Recent Carnival of Crime.”

Other notable items in Madsen’s collection include:

• Military discharge papers from 1783 signed by George Washington.

• A Revolutionary War-era letter signed by Thomas Jefferson during his time as governor of Virginia.

• A signed studio portrait of Theodore Roosevelt.

There are more than 300 items up for auction in the collection. See details and descriptions at HA.com/6335.