Conversation so far:
How many minor league teams are there in baseball?
There are 256 minor league teams.
What are the minor leagues in baseball?
A hierarchy of professional baseball leagues in the Americas that compete at levels below (MLB) and provide opportunities for player development and a way to prepare for the major leagues.

Question: How did he do in the minor leagues?
Self-contained rewrite: How did Casey Stengel do in the minor leagues?