He argued that his memories and opinions were more natural and candid if spoken, rather than written down.
Other versions of the autobiography were published in 1924, 1940 and 1959, but all with heavy edits and none true to Twain's vision.
In addition to sections devoted to his early life in Hannibal, Mo., his travels as a journalist and family years in Elmira, N.Y. and Hartford, Conn., the book contains his strongest political views.
Among his targets was contemporary Cecil Rhodes, who championed racist policies in colonial Africa and for whom the university scholarships were later named.
Twain, whose abolitionist views strengthened over time, writes that he wanted to hang Rhodes with a rope.
He also reflects on his early exposure to slavery on his uncle's farm in Missouri and the model for Jim in his most famous book, "Huckleberry Finn."
"In my schoolboy days, I had no aversion to slavery," writes Twain. "I was not aware there was anything wrong about it."
Twain also lambasts the government for sending soldiers he called "uniformed assassins" off to "imperialist" wars in Cuba and the Philippines.
"Patriotism is usually the refuge of the scoundrel," wrote Twain in 1908. "He is the man who talks the loudest."
Hirst said Philippines could be switched for Iraq.
"People are struck with how similar and applicable it is to today," she said. "All of the criticisms he made still apply."
Twain didn't spare the tycoons of Wall Street either, whom he accused of greed and selfishness.
"The world believes that the elder Rockefeller is worth a billion dollars," writes Twain. "He pays taxes on two million and a half."
Americans are still fascinated by Twain, even a century later, according to Cindy Lovell, executive director of the nonprofit Mark Twain Museum, which operates out of Twain's boyhood home in Hannibal, Miss., and receives 60,000 visitors a year.
"It's a wonderful read," she said. "All the Twain fans are eating it up like candy and they are reading it more than once."
Twain was the first celebrity who was "famous for being famous," according Lovell. He held court before presidents, artists, industrialists, and even European royalty.
President Ulysses S. Grant, tycoon John D. Rockefeller and abolitionist Harriet Beecher Stowe all were close friends.
But the road to that celebrity took its toll.
One bad investment in a typesetting machine created by inventor James Paige nearly devoured his life savings. In the autobiography, Twain lashes out against Paige for the scam in "very strong language," according to Lovell.
"He talks about having his nuts in a vice," she said.
On the verge of bankruptcy in 1893, Twain embarked on a lecture tour throughout the Southern Hemisphere to recoup his losses, writing about his travels in "Following the Equator."
"He had suffered poverty as a boy and near poverty as adult," she said.
"This was a guy who worried about money," she said. "When he died, he was on top, but he knew the stress of having his back against the wall. He wrote with one eye on the market -- if he signed his name on a grocery list, someone would have bought it."
Just after the tour ended in 1896, Twain and his wife Olivia and their second-born daughter Clara -- the only one to live into adulthood -- went to England to rent a house in Guildford, where costs were lower than in the United States.