When I was 6, and my older brother 9, my Dad built us a "Train board", as it was forever called. My Mom, who passed in 2017 at 94 years of age, always referred to WarrenvilleRailroad as my "Train board" even after all of those years.
The Train board that my Dad built was approximately 6' by 7', designed to fit into a queen size bed frame so that it could be rolled around and stood on edge in the common hall of the 2 family apartment house we lived in when it was not in use.
It was simple, painted green and sprinkled with green sawdust while the paint was still wet. The tracks were O27 with a loop around the perimeter and a single passing siding on one side, O27 automatic switches. Scenery was coffee cans representing oil tanks and a cardboard box as a tunnel. We did have Plasticville people that I remember my Mom painting at the old kitchen table.
Power was a 110 watt LW transformer. Our train set consisted of a Milwaukee Road GP7 (turning it upside down to listen to the horn was cool), a red gondola, a New Haven 6464 boxcar, a flat with Cooper Jarrett vans. an Alcoa covered hopper (Opening and closing all of those little hatches fun too) and a red caboose.
I remember this "train board" and those trains vividly to this day. I endlessly ran them around the "inner loop" and then the "outer loop", back and forth, over and over again. Never got boring to me.
I recreated my long lost set as one of my first adult train purchases back in 1983:
When not running the trains they always went back into their tattered boxes and the horn battery always came out of the engine. My Dad showed me how to do that after showing me the damage to a chrome EverReady flashlight from leaky D cell batteries. My brother and I knew that if we did not take care of our trains we would never get another set. After all, the set, its upgraded LW transformer, the added track and the 2 switches cost almost 2 weeks of my Dad's take home pay.
A year later my parents bought a small ranch style house with an unfinished basement. The "Train board" never needed to be stood on its edge anymore but my brother and I did roll it around to make room to play with other stuff in the basement.
Some Plasticville appeared on the layout (and I don't recall how or from where). A Hospital with the floors and furniture/equipment, a Church and a Motel. Plastic pine trees that you could take apart and put back together too. The Motel came with 3 plastic automobiles that we could play with.
The first Christmas in the new house was wonderful with a gift for us of a track cleaning car, the second Christmas Mom and Dad gave us an operating aquarium car.