The Mormon Kingdom on Beaver Island, Michigan--Interesting Random Facts
My 5th Grade teacher did a whole unit on Michigan's history, in which he included the Mormon Kingdom.
Ever since then, it's been one of those strange little tidbits from school that I've kind of half remembered, and occasionally wondered if it was a real thing or if I was just remembering it wrong.

So I Googled it just now.
Wikipedia article on The Mormon kingdom on Beaver Island.
And an NPR show How a Mormon king shaped a sleepy island in Lake Michigan