Tom, welcome to OOTP and these forums.
I am not too familiar with historical play, fictional or not. However, I think I can point you in the right direction.
I believe you need to select 1901 Settings in the Fictional League Creation Wizard (see first screen print). Then you need to look at the Progressing Options in League Setup, Options (see second screen print).
See the manual for more information on these settings:
OOTP Baseball Manual - Options Page
You can also search these forums for more information on these topics, and hope that somebody more knowledgeable than me will post their suggestions here (such as myasu, who posted while I was typing this).