re: Across America on a motorcycle

Did the Sturgis trip on my bike in 15. Had a great ride there and back. One thing I would suggest is stop when you need to. Nothing worse than pushing through and being miserable because this is supposed to be an enjoyable experience. You only have to stop for a few minutes to stretch your legs and you should be fine. Also, drink lots of water if you are traveling in the summer months. It was a bigger deal than I realized.
What kind of bike are you going to ride, that can make a big difference.
Enjoy the trip, and I can let you know of some points of interest along the way depending on your route