If you count UP based on the operation of through passenger trains over C&NW and MILW, then you should count GN & NP for through trains over CB&Q. None of these were trackage rights operations.
GN/NP are listed under #4.
What about the L&N as the C&EI carried the Hummingbird into Chicago.
Don’t believe the L&N owned the C&EI.
The L&N was already counted as an Illinois railroad via its line to St. Louis. The UP, GN, and NP didn’t own or directly operate any lines in Illinois.
The L&N explored merging with the C&EI in the 1960’s. They ended up buying a large enough amount of C&EI stock to block the Missouri Pacific from exercising control. Then, MP and L&N cut a deal to split the C&EI in two, with joint ownership of the double track line north of Woodland, IL into Chicago.
The MP briefly ran the entire railroad from 1967 to 1969. I grew up on the C&EI Evansville line and the L&N-side guys hated the MP for ransacking the Evansville line before it was conveyed to the L&N.
St. Louis did have a lot of trains, I think we were second busiest in US, we could go anywhere without having to use Chicago. We might have had to change trains but no problems getting there. Part of that was due to Dad’s pass , we could never ride the elite trains, worst trip was to FL, changed trains 3 times and had layovers of 2 hours or more. But we were in no hurry and loved riding trains anyway. Best run was joint train City of St. Louis, never had to change. They would switch our car from Wabash or N&W later at KC, to UP and then at Ogden to SP but we did not have to get off. Mom stayed on while Dad and I got off and she would wave to us roaming around as she was being switched. She said I came to ride a train and that is what I am doing. Dad had to pay extra fare for that train, but at least we got to ride it. Free from St. Louis to KC but l/2 fare for the rest of trip. But not that expensive in those days.