Mark Twain’s“Life on the Mississippi '' is a memoir of Mr. Twain’s experiences when he was a steamboat pilot on the Mississippi River. This book is half a history book and half a memoir of his moments. He basically tells the story of the river, his personal story with the river, as well as the part it had on his life growing up.
It’s a different approach than Frederick Douglas, who wrote a memoir of his life as a slave. He also uses the Narrative to write a paper on abolishing slavery when he tells the reader his journey and battle to become a freeman. He pretty much used his book as a way to get his message about abolition, this is why he uses real names of people or places etc.