I got a bit carried away in researching the history of this Twain-related landmark, but for those interested, here is a rewrite of my entry on this location in "Twain's Geography". The early days - up to and including the Civil War drew the interest of some eminent authors of those times. https://twainsgeography.com/location/cairo-il -- /Unaffiliated Geographer and Twain aficionado/