What did Mark Twain's name really mean?

Mark Twain, was born Samuel Langhorne Clemens, in Florida Missouri, 30 November, 1835. At the age of 4, Mark's family moved to Hannibal Missouri, a river-port town on the Mississippi River. At age 12, Mark became a typesetter, and soon after began contributing articles for publication. Mark worked on river boats and even became a pilot at age 21, which is where he heard the phrase (mark twain). The term signifies two fathoms or 12 feet on the line used to check river depth. Mark's love of river boating is why he started using Mark Twain as his pen name. As an adult, Mr Twain is known for being, a humorist, writer, entrepreneur, publisher, and lecturer. As an author Twain is best known for his books,"Tom Sawyer",and "Huckleberry Finn", which both are about life on the Mississippi River.

Mr Twain became especially well known for his humorous quotes, which he used in his lectures, and they were also widely printed in newspapers.