From the Nashville Daily Press and Times, April 21, 1866.
“The Challenge Accepted.–Recently the Rock City Base Ball Club challenged the Cumberland Base Ball Club to a test of strength. The challenge has been accepted, and Saturday next, at three o’clock P. M., fixed as the time, and the grounds near Fort Gillem selected as the place for the trial.
The following gentlemen have been chosen officers of the Cumberland Base Ball Club: John W. Dickens, President; Mr. Whitney, Vice President; F. Sanford, Secretary; and A. Hamilton, Treasurer.”
The announcement implies that the Rock City specifically challenged the Cumberlands to the match, but it’s more likely that the Cumberlands organized in response to a more general challenge. In any case, considering the speed of this formal organization, the Cumberlands must have been in the process of putting together a club beforehand, and perhaps even were aware of the Rock City.