Samuel Langhorne Clemens was born in Missouri in 1835, but the name Mark Twain didn't exist until years later. After working as a printer, typesetter, riverboat pilot, and a miner, Clemens got a job at a newspaper, the Territorial Enterprise in Virginia City, Nevada, in 1862. The newspaper was influential and the staff was young and daring. They often wrote stories that played hard and loose with the facts and rubbed readers the wrong way. Later in life, Clemens made up stories to make a point, but printing hoaxes in a newspaper made him enemies.
Authors often work under a pseudonym to keep their professional and private lives separate. We don't know if this was the reasoning behind Clemens using the name Mark Twain, but it happened while he was at the Territorial Enterprise. It didn't work, as people hated what Twain published as much as they hated what Clemens wrote, and he was pretty well known on sight. By 1864, an exchange of insults with a rival publisher led Twain to challenge the man to a duel. Read about those days, and how Twain left Virginia City in disgrace, at The American Mind. As an aside, don't get discouraged by the first two paragraphs, which are incomprehensible compared to the rest of the article. -via Strange Company
