Samuel Langhorne Clemens, best known by his pen name Mark Twain, is the subject of a three-volume biography titled "Mark Twain: A Biography" written by Albert Bigelow Paine. Clemens's personal and literary life is covered in the first book up to the year 1885, while the second volume carries on the narrative until his death in 1910. The biography gives a thorough overview of Clemens's life, from his early years in Missouri through his successful writing and public speaking careers. To provide a complete picture of the person behind the pen name, Paine consults a variety of sources, including Clemens's own works, correspondence, and interviews with family and friends. The first book of the biography focuses on Clemens's early years and professional life, including his years spent growing up in Hannibal, Missouri, his time spent learning the printing trade, and his time spent operating riverboats on the Mississippi River. It also discusses his early literary endeavors, such as his employment as a journalist and his early drawings and tales. The early years of Clemens's marriage and fatherhood are also covered in the book, including his union with Olivia Langdon and the birth of their children. It details his battles with professional and financial setbacks as well as his ultimate triumph as a professor and writer. In conclusion, "Mark Twain: A Biography" is a thorough and fascinating study of the life and career of one of America's most well-known authors, offering insights into both his personal and literary life.