Sentence:  Still, the Colonial League experiment was successful enough in its first season for the Federals to become interested in pursuing it as a <WSD>farm league</WSD> for its excess players. 
Meaning of the word marked with <WSD> tags:  One or more minor league teams owned by a baseball franchise and used as a training and testing ground for rookies, who, if they perform well, move on to play in the main major league team.