Lionel was Marx I believe. American Flyer was A. C. Gilbert out of New Haven. My dad had some and I got them up and running when I was in my 20’s. Really heavy and highly detailed. (Gilbert also made the Erector set) We got some Lionel trains at a local tag sale that my son has been playing with occasionally.
At the Eli Whitney museum, a couple months ago, they had a big American Flyer set up going and we went down and took turns controlling the different trains in the set up. It was pretty cool.