A meeting of the State association of base ball players was held last night in the rooms of the St. Louis base ball club, on Pine street, between Sixth and Seventh streets, when there were fifteen delegates present. The resignation of J.B. Ketterer, president, and J.S. Foster, vice president, were read and accepted. Mr. Miller was elected president of the association, and Mr. S.L. Steth vice president. The charges which the Atlantic club had preferred against the St. Louis club were withdrawn. The meeting adjourned until the first Friday in August.
-Missouri Republican, July 2, 1870
It's possible that the association simply held their elections for officers in June or July and this is just a new election. But it specifically states that Ketterer and Foster resigned. So I don't think that's it. I think this was an election that was held because of the resignation of the top two officers of the association. It's possible that their term was up but that's not how I read this squib.
Why would they resign? I have no clue. Smith resigned in 1869 to devote himself fully to business. He had been involved in the game for a decade, providing extraordinary leadership and vision, but I understand why he felt it was time to get out of the game. I don't know enough about Ketterer or Foster to make those kinds of judgments. They're not names that I recognize and can't find them in my notes.