2nd The International League disbands. Syracuse, Toronto, Hamilton, and Buffalo split off to form the International Association, while Newark, Jersey City, Wilkes-Barre, and Scranton become the nucleus of the Central League.
7th The Arbitration Committee meets and grants reserve rights to minor league clubs for the first time. In the most prominent contract dispute, prospect Bug Hilliday signs with minor league Des Moines, despite the claims by ML St. Louis.
8th In a controversial move the AA doubles its basic admission price to 50 cents. In late August 1888, the league, suffering from decreases in attendance and revenues, reinstitutes the old admission fee.
12th A baseball reporters association is organized. It pledges to work to standardize scoring practices, especially in the gray area of stolen bases.
13th Von der Ahe completes his biggest deal selling Bob Caruthers to Brooklyn for $8,250. The deal was delayed by Caruthers’s negotiations with Brooklyn, but he finally agrees to $5,000 for 1888.
15th The Texas League is organized at a meeting in Austin, thanks largely to the efforts of John J. McCloskey.