All of them, Katie.
Pennsy because my Grandpa was an Operator and because Dad&I rail-fanned The Hill.
B&O because I watched Covered Wagons yanking and shoving trains up from the Allegheny River crossing at Mosgrove through Gumtown where Grandma&Grandad lived and because we took The Capitol out of Pittsburgh and several excursions out of Pittsburgh.
The Reading because Reading Rambles.
Santa Fe because I rode in the cab of a GP9 from Grand Canyon to Williams Junctio and return and because several trips on The Chief and The Grand Canyon.
The UP because rode and watched many trains.
That's a start. More later.
Lew