Coincidentally, in the book, Ship of Gold, there's a story about a young man in 19th Century Keokuk, Iowa who after reading a sea captain's account of the Amazon River decides to leave home on an adventure to see it. He travels down the Mississippi to New Orleans confident he'll find a ship to take him Brazil. No ship offers passage, so the young man, Samuel Clemens, has no adventure to write about other than his experiences on the Mississippi.