Michigan was once the manufacturing center of this nation.

[HereSince1628]

15. Michigan like much of "The Old Foundry" states depended on heavy industry

Mining of iron and copper, mining of limestone (MI had the worlds largest open pit quarrythat mined the limestone used to make coke a fuel that burns hotter than coal alone), Great Lakes shipping (remember the Edmond Fitzgerald), smelting/steel making.

Lots of those jobs weren't lost from America. They "went South", when southern states aggressively subsidized industrial relocation. Part of that was opportunity to modernize on the cheap, part of that was escaping unions and their benefit demands. NAFTA made it all that much worse. But "right-to-work" was a bitter phrase in MI for decades before that.