I hate to ruin it for the OP .
we have been to the Field Of Dreams , and so forth on our trip from Bend Oregon to Bowdoin College Maine using US Highway 20 all of the way across .
There is a book we used that referenced everything to see on US Hiways including Hiway US 20 .
Iowa does have beautiful Tourist Info Centers as I recall
the distance from ABQ to Dyersville is 1189 miles .
In Wichita there are some air museums.
Not a lot of high spot memories were made on our drive across the USA which included all of Iowa .
Sorry if I ruined it .