The average 8 year old knows the dates of the First and Second World Wars.
American/World history starts a couple grades later based on my experience and the only dates I was remembering at that age was for the War of 1812
I also remember being taught much more about the Revolutionary War and Civil War than either of the world wars. Next to nothing about Vietnam or the Gulf war. Also remembered WW1 being slightly glossed over and learning 2-3x the material about WW2. I’m sure everyone’s grade school experiences are different tho lol