NEW YORK (AP) — Mark Twain was the kind of man who might tell an off-color joke, then grievously apologize, who wrote stories and essays he knew would offend and kept others private for the same reason.

A century after his death, Mark Twain remains censored, and uncensored.

The author and humorist worried enough about what he could say in public to withhold anti-religion essays and to forbid his autobiography from being published until 100 years after his death. The first of three planned volumes of the unexpurgated version, released in 2010 and including harsh words for American business and military actions, became a surprise best-seller that has sold hundreds of thousands of copies.

But Twain also believed in getting out the truth. “The Adventures of Huckleberry Finn” angered respectable people when it came out and still stirs a fuss 126 years later. Twain’s most famous novel has been paired with “The Adventures of Tom Sawyer” in a volume to be published next month by NewSouth Books that replaces the “N-word” — an offensive but often-used expression in the 1880s — with “slave.”

“He was profoundly a Victorian gentleman, or tried to be,” says Twain biographer Ron Powers. “It mattered to him if his wife approved of what he wrote and he was eager to please the public. But there were categories, like race, before which he was intrepid. In San Francisco before the Civil War, he was run out of town because he was criticizing the police for beating up Chinese people.”

“He walked a line where you could fall off on either side, to be much too conservative or by going so far that what you think is funny is not funny,” says Robert H. Hirst, general editor of the Mark Twain Project at the University of California at Berkeley, where the autobiography was edited, then released by the University of California Press.

“He said early on that the only criticism he’s interested in is that of the great general public. He’s aiming at this big audience. He wasn’t a ‘Not Ready for Primetime Player,’ like on ‘Saturday Night Live.’ He was a ‘Ready for Primetime Player’ and was watching where he was on the line.”

“Huckleberry Finn” comes as close as any book to the elusive status of “The Great American Novel.” But its frank narrative about manners, race and rebellion in pre-Civil War time makes it an uncomfortable classic. When first published, “Huckleberry Finn” was criticized for advocating bad behavior, for being a “coarse book not likely to set a good example for the young,” says Justin Kaplan, author of a Pulitzer Prize-winning Twain biography.

Over the years, as values changed, so did the objections. The N-word led to the book’s being removed from class readings lists. Some of the novel’s closing scenes, when Huck and Tom delay freeing the slave Jim and place rats and snakes in his shed, have baffled historians as cruel and gratuitous.

“Some people feel this is Mark Twain’s satire on reconstruction and how difficult life was after the Civil War,” Powers says. “No one is really sure. It may slip back into minstrelsy. I don’t know,” he said, referring to the offensive shows that offered ethnic stereotypes in blackface.

Altered literary works have been around a long time, especially during the 19th century, when Victorian standards led to sanitized Shakespeare. For decades, the Loeb Classical Library published watered-down versions of Greek and Roman texts, only to reverse itself after the 1960s and put back in the dirty words of Aristophanes and others. In the late 1990s, a new edition of Aesop’s Fables showed a far bawdier side than simple tales such as the Tortoise and the Hare.

“Huckleberry Finn” has long been out of copyright and subject to the wishes of anyone who cares to release it. The standard text for “Huckleberry Finn” is available through numerous publishers, but other versions are around. An edition without the N-word for grade schoolers, “retold from the original,” is part of Sterling’s Classic Starts Series, which includes books by Twain, Robert Louis Stevenson and Jonathan Swift.

“The books were abridged in a number of ways to make them appropriate for a third- and fourth-grade reader — length, sentence structure, difficult vocabulary and issues that might be too sensitive or confusing for a young reader,” says Frances Gilbert, vice president and publisher of Sterling Children’s Books.

An edited “Huckleberry Finn,” issued through Signet Classics, restores a chapter about rafting from the original manuscript and condenses other scenes. John Wallace, a teacher at the Mark Twain Intermediate School in northern Virginia, published a version of “Huck Finn” about 20 years ago that used “slave” rather than the N-word.

Scholars have objected strongly to the edition of “Mark Twain’s Adventures of Tom Sawyer and Huckleberry Finn” from NewSouth, although the controversy so far has resulted in few advanced sales; the book ranked No. 50,999 on Amazon.com as of Friday afternoon. Twain biographer Kaplan said he was “bitterly amused” by the new text. Powers calls the changes an “abomination” and a disservice to education.

”’Huckleberry Finn’ and the use of ‘nigger’ is the ultimate teachable moment in American literature,” Powers says. “It cries out for conversation between teachers and students. It cries out for context.”

The book’s editor, Twain scholar Alan Gribben, writes in the introduction that he had taught Twain’s work for years and that students were relieved when he chose not to recite any troubling words. He said softening the language would bring new readers and described Twain as “a notoriously commercial writer who watched for every opportunity to enlarge the mass market for his works.

“He presumably would have been quick to adapt his language if he could have foreseen how today’s audiences recoil at racial slurs in a culturally altered country,” Gribben writes.

“That’s ridiculous,” Powers said. “It’s like people who ask what would Mark Twain think of women’s lib? You can’t assume that and then use that as a pretext for eviscerating a work of art.”

“That is completely disingenuous,” adds mystery novelist Walter Mosley, who wrote an introduction for a book of Twain detective stories. “They can say, ‘Well, Mark Twain liked to make a buck.’ But he’s not making anything out of this.”

Copyright 2011 The Associated Press.