I mapped Sam's journey from Keokuk to New Orleans, via Chicago and Cincinnati, for those of you interested in such things. Any commentary is from the Mark Twain Project's collection of letters and editorials. I'm still trying to sort out the history of the railroads involved. I'm discovering just how corrupt the development of railroads was. http://twainsgeography.com/content/starting-out-amazon If anyone knows of commentary on Sam's first trip with Horace Bixby I'd appreciate a lead on it. About all I know is Sam got aboard the Paul Jones in Cincinnati, ran aground near Louisville, dropped of armaments at Baton Rouge and discovered that passage to the Amazon was not immediately available fro New Orleans.