Michigan’s Forgotten Christmas Eve Massacre

Michigan’s Upper Peninsula and the Finnish immigrants whose descendants still make up the plurality of its inhabitants aren’t the first things that come to mind when thinking about American labor history – or anything else, for that matter.

The “UP” occupies a marginal position in the national imagination. Sandwiched between three different Great Lakes, it covers one-third of the state’s landmass but boasts only 3 percent of its population. Its largest city, Marquette, has just twenty thousand residents. Cartographers sometimes mistakenly depict the peninsula as part of Wisconsin — or...