It only took us a century and a half, but we may have finally learned the real source of Samuel Clemens' ubiquitously recognizable nom de plume: he stole it from a humor journal so lame that he quickly invented a cooler story to pass off as true. But he wouldn't have gotten away with such a trick today.

The theory is according to a find by a Texas book dealer and scholar, who managed to stumble upon what seems to be the first recorded appearance of the name "Mark Twain"—in a humor journal called Vanity Fair (no, not the contemporary magazine) two years before Samuel Clemens adopted it. Thankfully, Austin's Kevin Mac Donnell was sharp enough to recognize the significance of his find, though he was really only poking around Google Books and modestly told the Los Angeles Review of Books that anyone could have done the same:

“I wasn’t looking for what I found. I stumbled across it,” Mac Donnell said in a phone interview. With a flair for folksy humor that made Twain famous, he also added that “you could train a cat to do what I did. You could train a garden slug to do what I did, but the cat would be quicker.”

Scholars have never been clear on the source of Twain's pseudonym, but stories emerged during his lifetime. One famously suggested "Mark twain!" was the writer's trademark cry in a Virginia City saloon he frequented, meaning "Mark two more drinks." Twain himself claimed an altogether different source for his pseudonym: he said the name had been used by Isaiah Sellers, a riverboat captain who died in 1863, and "as he could no longer need that signature, I laid violent hands upon it without asking permission of the proprietor's remains."

But that's been in question for quite a while, particularly after researchers scanned Sellers' river reports and found no appearance of the Twain name. Plus, Twain himself cheekily cast doubt on his own version of events late in his life. Mac Donnell's find, by contrast, adds up pretty well: Twain was known to read the short-lived humor journal, which lasted only from 1859 to 1863, and he even used some jokes by the journal's chief writer, Artemus Ward. Why obscure the source, then? Besides the obvious fact that the riverboat tale made for a better story, Mac Donnell's theory is simple—the journal wasn't funny, and Twain knew it:

And then there was the stigma of being associated with Vanity Fair: the fact that its contributors, the so-called “Phunny Phellows,” were, well, not funny. “By the time Twain became famous, they were going out of style pretty quick,” Mac Donnell said. A specialist in 19th century literature, he added that: “In 1873, when Clemens was challenged on the source of his pen name, he had already patented the Mark Twain scrapbook. He had already branded himself Mark Twain. He had signed book deals and established his name. He wasn’t about to go backwards into the Phunny Phellow mold.”

The LARB heralds the story as an indispensable example of Twain's savvy self-branding, of how shrewdly he talked up his folksy Missouri roots and concocted long-lasting stories to go along with it. Rightly so. But it's also a fine indicator of just how much writers of Twain's stature could get away with in the 19th and early 20th century, borrowing ideas or names wholesale, before the Internet sprouted its own cottage industry of fact-checking, myth-busting, and sourcing. Had he adopted his pen name today, Twain's decidedly uncool namesake almost certainly wouldn't evade detection—we'd know plenty about his early life, and we'd probably have his yearbook photo on file, too.

But, Twain famously wrote in a letter to Helen Keller, "all ideas are second-hand, consciously and unconsciously drawn from a million outside sources," and "ninety-nine parts of all things that proceed from the intellect are plagiarisms." And the writer knew better than anyone: some sources are cooler than others.

All photos: Associated Press