Love the, "We used to do it with the...." replies.
Maybe you did. It was a different time and place. Lots less traffic. Lots less distracted/fatigued/unskilled drivers on the road. Different vehicles. Lighter trailers (i.e. fewer "creature comforts"). Different attitudes (i.e. you didn't get shot for going slower than the flow of traffic, for example).
Bet if you could ask him now, Dad would probably admit that towing with that old wagon was pretty sketchy.
No doubt you got away with it, but that does not mean things were better back then.