The Letters of Mark Twain, Complete [by Mark Twain]

These letters give us some degree of insight into the evolution of Twain's style of speech and prose over his lifetime. We see in them the development of his trademark "grotesque exaggeration"--his "gentle resignation to disappointment." They are a small window into the psyche that created the various characters of his stories. But The Letters of Mark Twain also reveal the tragedies of his life: the lack of success in his business ventures, the passing of family and friends. 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. 

LibriVox recording read by James K. White.

link to the free audiobook
The Letters of Mark Twain, Complete [by Mark Twain]