The Union War inspired the formation of "reserve teams". These were auxiliaries of the major league clubs made up of youngsters recruited from semi-professional and amateur ranks. They were paid salaries and played regularly scheduled games with each other, charging twenty-five cents admission. The purpose of these scrub teams was to keep as many players as possible out of Union control and at the same time to siphon away customers from Union parks. Of course, there was always the possibility, as Chris Von der Ahe explained, that these teams might be a means of developing new talent for the parent club, and even supply replacements in emergencies. The reserve teams were also used to keep the regulars on their mettle. The St. Louis Browns were well aware of this, having grown tired of hearing, "If you don't play well you will be dropped to the reserve crowd." ... Temporary expedients of war though they were, the reserve teams bore the closest resemblance to modern baseball's farm system yet discernible. (From Chapter 14)
David Nemec (The Beer and Whiskey League) notes that “in the spring of 1888... Von der Ahe formed the St. Louis Whites as a kind of farm team to play in the Western Association,” while Peter Morris (A Game of Inches: The Game Behind The Scenes) writes “St. Louis Brown Stockings owner Chris Von der Ahe operated the St. Louis Whites of the Western Association as a farm club, signing no fewer than twenty-nine players to 1888 contracts by December of 1887.”
Clearly the St. Louis Whites in 1888 were not a response to the Union War, which ended after the 1884 season. There were concerns by other clubs at the time that the involvement of Von der Ahe in the Western Association may have been in part motivated by an interest in having an expanded pool of players for the Browns. Jeffrey Kittel investigated this premise in his blog about the history of 19th century St. Louis baseball (This Game of Games). (Sadly the original blog posts no longer exist.) While he never came to a firm conclusion, he demonstrated that aspects of the relationship between the Browns and the Whites looked like that between a parent club and farm club. He also suggested that this was not the primary motive for Von der Ahe when he formed the club. The intent may have been to protect his baseball interests in light of rumors of a new, Eastern Major League, which would have resulted in the end of the American Association. After reading some of the newspapers from the summer and fall of 1887, during which time the Western Association was first conceived, I tend to agree with this notion. While the Western Association never claimed to be a major league, the foundation for such a jump was present should the proposed Eastern League take shape and the American Association collapse. The presence of clubs in the three western-most major league cities (Chicago, St. Louis and Kansas City), as well as the participation in the Western Association by the owners of the major league clubs in St. Louis and Chicago, suggests that those owners were looking at a back-up plan should they be cut out of a new Eastern-city only major league.
After the Western League was organized in the fall of 1887, Von der Ahe and manager Tom Loftus went on a signing spree, signing several dozen players for the Browns and Whites for the 1888 season. The St. Louis Republican listed 14 players for the Browns and 14 more for the Whites in December of 1887. A listing in the St. Louis Post-Dispatch adds a few more players, bringing the total listed under contract identified in articles over the winter of 1887-1888 to 31 players. Not all of these appeared in regular season games for the Whites or Browns in 1888. One player, Bug Holliday, was ruled to have been signed improperly and was granted to Des Moines in the Western Association for 1888. The complete list of players identified with the Browns and Whites by February of 1888 is as follows: