
Mark Twain is the name printed on books such as The Adventures of Tom Sawyer, but it was not the author’s birth name. He was born Samuel Langhorne Clemens. Mark Twain was his pen name, also called a pseudonym: a name a writer uses publicly instead of a birth or legal name.
The name connected his writing identity to his earlier work on Mississippi River steamboats. In riverboat language, mark twain was a call based on a depth measurement. It indicated two fathoms of water, or about 12 feet. Clemens later adopted the phrase as the name under which he wrote.
Example: Samuel Clemens wrote The Adventures of Tom Sawyer, but the book identified its author as Mark Twain.
Writers may choose pen names for privacy, branding, or a memorable public identity. A pen name does not make the writing less genuine; it simply gives the writer another professional name. In Clemens’s case, the choice also reflected a world he knew personally and later described in his work.
- Birth name: Samuel Langhorne Clemens
- Pen name: Mark Twain
When discussing the person’s life, both names can be useful. “Samuel Clemens worked as a riverboat pilot” emphasizes the historical person, while “Mark Twain became a celebrated author” uses the name familiar to readers.

