Minnesota is the land of Paul Bunyan. Although I did see at least one place in the U.P. attempt to claim him, Minnesota wins by sheer number.
Perhaps the best stop on the way to Duluth was at a lovely park. 
In case you don’t like the Star Wars angle of the historical marker (not my doing, I assure you), the caption reads:
SUGAR POINT BATTLE
When a federal marshall with
about 100 troops of the 3rd
infantry tried to arrest the
Chippewa chief Bugonaygeshig
at Sugar Point opposite here
on the northeast shore of the
lake a sharp fight occured
October 5, 1898. The Whites lost
7 killed and 16 wounded and the
arrest was never accomplished.
In Duluth, I saw tall ships.
Including a small one before the larger ships and tourists arrived.
There was also the world’s largest rubber duck, but she seemed to be something of a fraud.
If you’re looking for food in Duluth, stop at Northern Waters Smokehaus. Outside you can see yet more egregious displays of plentiful potable water.
If you want coffee and baked goods, stop by the Duluth Coffee Company, though the latter seems to arrive quietly at variable times in the morning and in rather small quantities. There is also the Lake Superior Bakehouse, but my experience there was somewhat mixed.
Oh, and make sure to walk down to the public beaches and swim. There are no pictures; I was too busy enjoying the water and the company of a new friend.