Many of Twain's works have been suppressed at times for various reasons. Adventures of Huckleberry Finn has been repeatedly restricted in American high schools, not least for its frequent use of the word "nigger", which was a common term when the book was written.

Unfortunately, a complete bibliography of his works is nearly impossible to compile because of the vast number of pieces written by Twain (often in obscure newspapers) and his use of several different pennames. Additionally, many believe that a large portion of his speeches and lectures have been lost or simply were not written down; thus, the collection of Twain's works is an ongoing process. Researchers have rediscovered published material by Twain as recently as 1995.

Early journalism and travelogues

Twain's first important work, The Celebrated Jumping Frog of Calaveras County, was first published in the New York Saturday Press on November 18, 1865. The only reason it was published there was because his story arrived too late to be included in a book Artemus Ward was compiling featuring sketches of the wild American West.

In 1872, Twain published a second piece of travel literature, Roughing It, as a semi-sequel to Innocents. Roughing It is a semi-autobiographical account of Twain's journey to Nevada and his subsequent life in the American West. The book lampoons American and Western society in the same way that Innocents critiqued the various countries of Europe and the Middle East. Twain's next work kept Roughing It's focus on American society but focused more on the events of the day. Entitled The Gilded Age: A Tale of Today, it was not a travel piece, as his previous two books had been, and it was his first attempt at writing a novel. The book is also notable because it is Twain's only collaboration; it was written with his neighbor Charles Dudley Warner.