Captain Isaiah Sellers (1802-1864)- Captain Sellers was the most famous of the steamboat men plying the Mississippi between St. Louis and New Orleans for more than 40 years.  He was the first man to use the pseudonym, “Mark Twain”, and after his death, Samuel L. Clemens adopted the same nom de plume because it always stood for truthful writing, as Clemons explains in his “ Life on the Mississippi”, Captain Sellers tombstone depicts the captain standing at the wheel of his riverboat.