The Brush Resolution was adopted by the National League and American Association early in the spring of 1898. The resolution was the brain child of Cincinnati club president John T. Brush, and was a response to "villainously filthy language" that was part of the lexicon of "a very limited number of players," but apparently occurred enough to cause concern among the press and the fans (p.198 "Address to Players"). Brush asked league umpires to send him examples of obscene language they had heard the previous season. He was appalled by what he received.
Certainly, the fact that crowds were closer to the action played a role in making language a thorny issue. Complicating the matter further was the relatively weak position of authority held by umpires of the era. Still, President Brush criticized umpires for not punishing players swiftly enough at the onset of vulgarity and bad behavior. He argued that it was imperative that umpires take charge on this issue and enforce existing rules, because owners fining players after the fact was not a satisfactory deterrent.
Locally, it is quite likely that some choice words were exchanged on the baseball fields of the Red River Valley in 1897, many directed at a game's umpire ("Fined and Released"). A quick search on Google for Brush resolution baseball produces a sampling of some of the language that the league hoped to stop (specific examples being too objectionable to post here).
The seventh section of the resolution provides a quick look at the nature of the problem and the punishments that would be possible depending on the severity of the offense: "The penalty for using obscene, indecent, and vulgar language, within the meaning and intent of this measure, is entirely within the discretion of the tribunal, and may be suspension for days, for months, for the unexpired season, for a year, or for life, according to the conditions, circumstances and nature of the offence (sic), it being the sentiment of the League that creates this law that an unwarranted, unprovoked, and brutal use of vulgarity to a spectator, or within the presence of spectators and within the hearing of ladies, should debar the offender forever from service with his club, or any other club, member of this League or subject to its jurisdiction" (p.196 "The Brush Resolution"). Based on the feedback Brush received in letters from league umpires, the Cincinnati president said that blacklisting players would not be an unreasonable punishment for some of the language and behavior cited in accounts that he received.
1898 Spalding Guide to Baseball
The Sporting Life "Brush is Bullish" Feb 19, 1898 p.11
(Post updated 8-19-12)