On Saturday, the 4th inst., the Unions of St. Louis paid a visit to Cincinnati and played the Cincinnati Club. Game was called at 10 A.M. The game was rather one sided, the batting of the Cincinnatis being remarkably fine, while the Unions found difficulty in hitting Brainard's and Howe's pitching - the two latter changing positions in the 6th innings, and in the 8th Wright pitching, with Brainard at 2d. The Cincinnatis' victory was greater than that of the Atlantics over the same club a few days previous...
-New York Clipper, July 11, 1868
But think about this for a minute: the Union Club, in 1868, played the Athletics of Philadelphia, the Atlantics of Brooklyn, and the Red Stockings of Cincinnati. That's a step up in competition. That was three of the very best clubs in the country and the Unions wanted to play them. Of course, they got crushed in all three games, with the collective score being 177-28 and a run differential of negative 149. So much for challenging for the national championship.
And the Red Stockings would come to St. Louis the following year and beat up on the Unions again.