Armistice Day 1918
When armistice talks started, Springfield's city leaders devised a system to alert the citizens of the results. There was no television. Radio was virtually non existent & phones were expensive & rare. A signal system was set up that factories would blow their whistles once every hour if armistice was reached & twice if rejected. When the whistles blew once at 1:45 AM, the town woke up, celebrations & parades erupted as everybody went downtown to rejoice. Businesses shut their doors, factories shut down, somebody left a sign on the door to city hall saying, "Nobody Home". Church and school bells rang and every kind of noisemaker was pressed into service. An official parade began at 3 PM.
This level of spontaneous organization is hard to imagine today when we have so much better communications technology. Thing is, it kinda isolates us, too. Sure, the Twitter servers would probably overload but would a broad swath of people actually physically come together? Would people tolerate the street closings? This wasn't a flash mob - it was a whole town.
The description of the events came from Tamara Dallenbach's Ridgewood in the Country Club District