Hannibal and St. Joseph Railroad Company. Hannibal, Mo., Hannibal and St. Joseph Railroad Office, 1860. Cover dated 1859. This stuff starts all sorts of thoughts going, even without being able to get at the books. A search of a Missouri university online catalog might be even more fruitful, of course.
Bicycle riding after lunch puts strange thoughts into one's head.
It occurred to me that an Annie search for the keywords 'geography frontier' might get me something useful, and so it did, the familiar mix of surprising, serendipitous and expected. Facts On File, c1995. Mainly covers the period 1754-1917. Yale University Press, c1988. Greenwood Press, 1989.