The Early Years of Baseball was a baseball holoprogram.
Designed by a friend of Judith Sisko, Judith presented to her brother Benjamin Sisko just prior to Sisko leaving Mars for Deep Space 9 in 2369. Judith suggested that she and Benjamin use the program with Jake, or for Sisko and Jake to use the program to pass time on their journey to DS9. (DS9 - Mission Gamma novel: Lesser Evil)