Virginia to Wyoming

Also look into US 50. We have taken it from our home in Indiana to Co. them north on US 385 to WY. and S.D.

Seems to me that seeking out the 4lane state routes, complete with town bypasses, is a cheat, getting the ease of travel of an Interstate without the traffic. I thought the whole point to taking local roads was to slow down for towns every 10 miles, and lolly gag behind a farmer tractor for a mile or two. Plus the fun of passing slow traffic on the two lane highway! Don't you miss the buffeting as a semi passes by coming the other way? And the glare of headlights at night?

But if you really want to go local, it's hard to beat bike packing. Years ago, in preparation for a Mpls to Chicago bike ride, I ordered a full set of Wisconsin county highway maps. With the exception of the granddaddy of all rail-to-trail routes, Elroy Sparta, I rode the lettered ('A', 'P', etc) county roads where possible. Only took me 6 days, and I still remember the route better than any car drive 40 years ago.

Thanks for all of the responses. This is the kind of information that I am looking for

One road we took was State Route 36 through rural Missouri. It is a 4 lane highway and the speed limit is 65mph. But it has way less traffic than I-70. There are 2 Missouri State parks along the route too.One is Long Branch and the other is Pershing.We stayed at Pershing in 2016. Nice camp sites with electric hookups,showers and dump station. It is right off Rt36 and I believe we paid $19 a night.

Without time constraints and willingness to take local roads, the options are wide open. It depends more on your interests and how 'local' of a road you can handle.

For example when we visited Virginia some years ago I used some geology field trip guidebooks, and ended up taking some rather minor roads (in a pickup). And also use Road Food to guide use to local biscuits and ham stands. On the return trip west (to Chicago), I chose roads through the heart of Dolly Sods. I also made a point of passing through a couple university towns (Bloomington IN and Columbus OH).

When I lived in Chicago and vacation further west I preferred to take freeways on the lest scenic areas, in order to have more time in the scenic mountains. Still I'm a sucker for rivers and lakes. State parks and wildlife reserves are often located on those.

Others talk of enjoying farm lands, cow feedlots, and slow small town streets (and local museums). Or historic ice creme parlors and burger stands. Seems the antique hunters just cruise the backroads with the intent of stopping where ever something catches their eye.

My approach is to learn what I can about points of interest, make a general plan, identifying critical spots (campgrounds that need reservations, special events on certain weekends, etc). Then just head out, modifying plans as you go. You may find, for example, that after a few days you've seen all backwoods hollers that you want, and choose to take a turnpike till you hit the flat cornfields of Indiana or Illinois. Or choose to meander north along the Mississippi before turning west.

We have enjoyed driving route 36 from Hannibal to St. Joseph MO. It's a divided highway with few trucks. Past St. Joseph route 75 goes north to join route 2 to route 34 at Lincoln NE. At Grand Island we pick up route 30 all the way to Ogallala. Route 30 parallels several miles from I80 along the North Platte River which was the route of the Oregon Trail. At Kearney is the remains of Fort Kearney (not much there). At Gothenberg is a restored Pony Express Station and in North Platte is the Bailey Yard of the Union Pacific Railroad. Begun in the 1860's as part of the original transcontinental railroad, it is now the largest rail yard in the world. The rail operations can be viewed from the Golden Spike Tower. At Ogallala we always take route 26 into WY to join I25. Along route 26 are Oregon Trail sites including Ash Hollow, Chimney Rock, Scotts Bluff, Fort Laramie (restored buildings there), plus the four ft deep Trail Ruts and Register Cliff in Guernsey. If you really want to get away from towns in WY, try route 220 from Casper to Muddy Gap and then route 287 to Lander. Independence Rock, Devils Gate and Split Rock Oregon Trail sites are along route 220.

The first federally assisted road is called the National Road or US Route 40. It goes from Cumberland, MD to Vandalia, IL and was instrumental in developing the new land back in the 1800's. It is some 600 miles long and if you are interested in traveling the back roads this one might be of interest.
And there is always the Lincoln Highway, Route 30 that goes coast to coast. It was the first to do so.

Here's a small part of it: From Grand Island, Nebraska, take Hwy 2 instead of Interstate 80. A good road through small towns, with nice scenery.