Mark Twain, the pen name of Samuel Langhorne Clemens (1835–1910), is one of America's most celebrated writers and humorists. Born in Florida, Missouri, and raised in Hannibal, he began his career as a printer's apprentice, eventually becoming a riverboat pilot on the Mississippi River. The pen name 'Mark Twain' itself is a river term signifying two fathoms deep. Twain's wit, incisive social commen...