The first base ball club was organized, and among its members were Maj. A.P. Morey, Ben. Lyon, E.H. Renish, and John Scheer.
-The History of Pettis County, Missouri
Founded in 1857, the town was a bit of a boom town as it became both a railroad hub and, during the war, an important Western military outpost. Beginning in 1866, Sedalia was a major terminus for cattle drives and the town saw a great many people moving in and out. In this atmosphere, with a population in flux and a growing number of new, young, male citizens, it's easy to see how the game could have been introduced and found fertile soil.
Interestingly, all of the factors that were present in Illinois in the first half of the 19th century and contributed to the spread of proto-baseball games in the state are also present in Sedalia in 1867. I've often found it difficult to explain why the study of the spread of proto-baseball games in the Trans-Appalachian West is relevant to the history of baseball in St. Louis but the similarities between, for instance, Jacksonville, Illinois in the 1830s and Sedalia in the late 1860s shows that the specific reasons why the proto game and the New York game spread across the nation were pretty much the same. If we have a better understanding of the process by which bat and ball games spread across the Trans-Appalachian West, we should have a better understanding of how the New York game spread across the country in general and how and why it came to St. Louis in 1859 specifically.
The real problem is that we don't have a lot of information about what was happening in St. Louis, with regards to baseball, in 1859. We have a lot of secondary sources but very little from contemporary sources. It leaves a large hole in our understanding of the history of 19th century, St. Louis baseball. What I've been trying to do is fill that hole in by understanding what was happening in the broader region, with the assumption that what was happening in Jacksonville in the 1830s is transferable to St. Louis during the same period. I've been trying to understand St. Louis baseball in the first half of the 19th century by investigating what was happening elsewhere during the period and where, by chance, we happen to have a lot more information.
It is, as I've said, a difficult argument to explain and I think I've done a poor job of it. But there is a reason why I'm interested in 1867 Sedalia and frontier Illinois. It may not be immediately obvious but it is relevant to the history of St. Louis baseball.