Brendan I. Koerner is a contributing editor at Wired and a columnist for Gizmodo. His first book, Now the Hell Will Start, is out now.

The nation will observe Labor Day this coming Monday, allowing millions to enjoy the waning days of summer, as well their last chance to wear white pants without earning a "tsk tsk" from Miss Manners. How did this early September holiday get its start?

Though President Grover Cleveland declared Labor Day a national holiday in 1894, the occasion was first observed on Sept. 5, 1882, in New York City....