I learned about the MPHS on-line. I found the MOPAC modeling group on Yahoo, and wanted to know more about modeling the Missouri Pacific during the 1950s. 
As for my interest in the Missouri Pacific, I grew up three blocks north of the Missouri Pacific tracks in Lincoln, Nebraska during the late 1960s and throughout the 1970s. My maternal grandparents lived in Aurora, Missouri, along the White River Division, from the early 1960s until the early 1980s. 

Coupled to my interest in the Missouri Pacific (and other railroads) is my interest in the Great Plains and the industries that grew up in the region; agriculture, flour milling, mineral and oil extraction, food processing, electric power production, etc.