Did Abraham Lincoln read – and write in – a book justifying racism?

If someone were to claim that an old book had been scribbled in by Abraham Lincoln himself, you might be inclined to take that claim with a grain of salt.

Especially if that old book was "Types of Mankind," a volume extolling the 19th-century theory that different races were actually different species, and that the Caucasian was the natural superior and fit to rule over all the others – a view that Lincoln was famous for opposing.

That's why, when historians confirmed that handwriting on the inside cover of "Types of Mankind" was indeed Lincoln's, they also stressed that the president, writer of the Emancipation Proclamation, was almost certainly reading the book in an attempt to better understand his opponents' point of view.

According to the Associated Press, the small Vespasian Warner Public Library in Clinton, Ill., had long known of rumors that the handwriting in the cover of the 1854 volume was that of Abraham Lincoln. But it wasn't until a new library director was hired that a decision was made to finally send the book to the experts this summer to see if there was anything to the story.

"We didn't know whether we should take it seriously," the library's Assistant Director Bobbi Perryman said, according to the Associated Press. Lincoln was known to write in books only very rarely, and this particular book did not bear any sort of recognizable signature.

According to Pantagraph.com, Lincoln had apparently borrowed the book from attorney Clifton H. Moore, a resident of Clinton and friend of the future president. The text in Lincoln's handwriting is an address so the book could be returned to its rightful owner: "Attorney Clifton H. Moore/Clinton/De Witt Co." Clinton is located in DeWitt County.

Under that inscription is an attestation by Lawrence Weldon, a mutual acquaintance of Lincoln and Moore, who wrote: "The above was written by Prest. Lincoln in 1861 - Just before he left for Washington. L. Weldon."

It was known that the book did come from Clifton Moore's personal library, who donated thousands of books that formed the basis for the Vespasian Warner Library when it first opened in the early 1900s, according to the Associated Press.

Even though the evidence pointed to the authenticity of the writing, there was no way to be completely sure it wasn't a clever forgery until it was taken to handwriting experts at the Lincoln Library and Museum. Once it got there, the historians quickly agreed that the handwriting was genuine, according to Pantagraph.com.

"There are certain letters of the alphabet that Lincoln wrote in a way that were not common to his era," James Cornelius, curator of the Lincoln Library and Museum said, referencing Lincoln's style of writing E's and N's. "A forger can typically do some of the letters in a good Lincolnian way. They'll give themselves away on a couple of the others. This all adds up."

Once Lincoln's writing was verified as authentic, the question became: Why was Lincoln reading such a blatantly racist book in the first place? "Types of Mankind" uses pseudo-scientific practices like skull measurements in an attempt to prove that Africans and Native Americans were actually different species, meaning that the Bliblical command to be kind to one's fellow man would not apply to these races, according to NBC5 Chicago.

If the attestation from Weldon is to be believed, Lincoln wrote in the book in 1861, the year he was inaugurated as President. However, he may have actually borrowed it in 1855, when he represented a DeWitt County resident who sued for libel when his brother-in-law spread the rumor that he was African-American. (The brother-in-law was represented by Moore, the book's owner.) Other theories are that Lincoln borrowed the book in 1858 to prepare for his famous debates with Steven Douglas, or that he borrowed it in 1860 for his presidential campaign.

Whatever the case, historians are almost certain that Lincoln borrowed the book to prepare for some sort of situation – either a legal case or a political campaign – in which it was advantageous to know what his opponents were thinking.

"Lincoln was worried that the whole idea that you could segregate one group of people based on some brand new thinking would just carry on into other realms,"  Cornelius Tuesday said of Lincoln, according to the Associated Press. "He could foresee the whole country coming apart over the issue that different people could be barred from different things based on different qualities."

For now, the Vespasian Warner Library is keeping their book hidden away in a safe, though they do plan to eventually restore it so they can put it on display for the general public.

Weston Williiams is a Monitor contributor.