

This post has been corrected. Please see note at the bottom for details.

Mark Twain will be honored by the U.S. Postal Service, which will debut a new Mark Twain "forever" postage stamp on June 25. A ceremony marking the first day of the stamp's issue will be held in Hannibal, Mo. That's the town where Twain grew up, and the place he used as a setting for his classics "The Adventures of Tom Sawyer" and "Adventures of Huckleberry Finn."

Twain had a surprise hit in 2010 when his massive "Autobiography of Mark Twain" was published. As instructed, the author's memoirs had been held for 100 years after his death, but no one expected them to be a bestseller -- except, maybe, Mark Twain. "Autobiography of Mark Twain," a whopping 736 pages, was only volume one -- two more volumes of his memoirs are on the way from the University of California Press, tentatively scheduled for 2012 and 2014.

Born Samuel Clemens in 1835, Mark Twain adopted his pseudonym from the calls of Mississippi riverboat workers. He started out as a reporter and went on to publish more than 50 books during his lifetime, and to become one of America's first celebrities.

The Mark Twain stamp is the 27th in the Post Office's Literary Arts series, which has included James Baldwin, T.S. Eliot, William Faulkner, F. Scott Fitzgerald, Ernest Hemingway, Ogden Nash, Edith Wharton and Tennessee Williams.

What might America's greatest humorist think of the honor? He was a big fan of the mail, but when it came to stamps, he had little more to say than that they were quite flat.

In his 1872 book "Roughing It," Twain wrote that he was about nine miles away from Mono Lake when he -- and all his gear -- fell off his horse in the dark. Two tough miners appeared at the noise. "A stone whizzed by my head," Twain wrote. "I flattened myself out in the dust like a postage stamp, and thought to myself if he mended his aim ever so little he would probably hear another noise."

Mark Twain has been as flat as a postage stamp before; he was on a 1940 stamp that cost 10 cents. "Forever" stamps, which cost the price of a first class-mail stamp -- 44 cents -- can be used even if the price of a first-class mail stamp changes. Even, ostensibly, for another 100 years.

For the record, 2:40 p.m. June 23: A previous version of this post said the price of a first-class mail stamp is 42 cents. A stamp currently costs 44 cents.

-- Carolyn Kellogg

Image: Mark Twain "forever" stamp. Credit: USPS