There are some tour routes that criss-cross the country, and that would help you get routes. If you had a driver for an RV and could do a century in 5 hours, I can see doing a century in all 50 states in 50 days. You could do some of them at two per day, for that matter. Come to think of it, to save time, you could do all the rides downwind and do some of them mostly downhill.
If you wanted to do an organized century or a scenic route in each state, it would get more involved.
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