Minnesota didn't become a state until 1817, Revolution was already over. Too far north to see any battles in the War Between The States, but the 1st Minnesota infantry regiment distinguished itself at Gettysburg.
Minnesota civil war soldiers were loaded onto trains and sent south, although I believe some confederate soldiers were imprisoned here. Google Minnesota in the Civil War and you will find out the history.
You got me curious about that question.
I agree about research.
Other than prehistoric finds, the oldest you'll get in Minnesota is the fur trade era.
That's what I'm into here in Manitoba.
You will find civil war items as many from your state enlisted and brought their uniforms back home after the war.
This was the case with hundreds of Manitoba Metis buffalo hunters. When the hunt was slow, they headed south and joined the Union.
There were military forts and posts in Minnesota as well.
If you look hard enough you may find something lost by the Vikings!
Cheers,
Dave.