There are a number of roster sets and a historical DB linked here:
www.ootpmodsquad.com. Look around to find what you need.
If you use a roster set the minors will be set up for you. If you use a Historical DB like Lehman or Arod/Garlon (try the latter) to set something up then you will have to create your own universe first. See the manual for more info or try the historical leagues section of the OOTP boards for more info.