Not a close call. Summer, 1980, Livermore CA (where my parents lived and I grew up) to Washingtom DC (where my aunt lived). I was with a friend as far as Yellowstone, on my own the rest of the way (he had family obligations - we are still good friends). We stayed for a few days with my friend's brother in Pocatello ID and I stayed for about five days with my grandparents in Pittsburgh PA, otherwise we/I camped every night. This was more than a bike ride. It was a major life event.
I planned the route. Here's where I/we went.