Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
Beings as your button looks to have a self shank iron back.
I would date it to the mid 1900's and would say it's a fashion or civilian button.
Military buttons almost always have a brass back.
Would it be likely that a Union Navy button would be in Minnesota? I'm not all that familiar with the naval activities up there during the War of Northern Aggression, but when trying to identify a relic, I try to consider location and what's most reasonable to find there. Doesn't always play out that way, but it's a good starting point.