These letters were arranged in two volumes by Albert Bigelow Paine, Samuel L. Clemens's literary executor, as a supplement to Mark Twain, A Biography, which Paine wrote. They are, for the most part, every letter written by Clemens known to exist at the time of their publication in 1917. They begin with a fragment of a letter from teenaged Sam Clemens to his sister, Pamela, and conclude with a letter to his attorney two weeks before his death.

These letters give us some degree of insight into the evolution of Twain's style of speech and prose over the period of his lifetime; they are a small window into the psyche that created the various characters of his stories.

But they also reveal the tragedies of his life: the lack of success in his business ventures, the passing of family. And as I read each one in this collection, I can almost detect the faint odor of one of his “devilish” cigars wafting across the room. (Introduction by James K. White)