Be careful not to crowd that itinerary.
Mindy, as you can see from the responses so far, there is much to see between Chicago and Portland. Over the months, until your departure, there are bound to be more added. as well as the ones you find yourself. There will be points of interest along a northern route, and along the southern route.... and the many routes in between.
Don't be overwhelmed, but choose carefully which you will include, lest you should not leave yourself sufficient time to really enjoy each one. Sometimes less is more! This of course also leads to the comments above about not just crossing off States. There is so much to see everywhere, and you'll want some flexibility for those surprise spots along the way. Sometimes it takes several visits to see all you want to along any given route, or in any State.
For example, next year I hope to be driving to and through Alaska for the fourth time. Want to see it all just one more time, in case I never get back there.
Lifey