A couple years ago we visited the Amana Colonies in Iowa. Very interesting history of which significant remnants remain. There is a huge cg in a pasture nearby. The Hoover Presidential Library and home are about 40 miles east in West Branch. We missed it

but plan to visit someday.

President Hoover was hugely popular at the time of his election but is now mostly remembered for the Depression which began on his watch.
In Dubuque you will find many remarkable churches and an aquarium devoted to the Mississippi River. Another future visit for us.
The drive north on US151 from Cedar Falls to Dubuque was a delight. It is a divided four-lane (not an Interstate). Our favorite kind of highway. It passes through rolling farmland.

Best wishes for a safe, fun trip!