Cap Girardeau Earthquake
The Cap Girardeau Earthquake, the largest earthquake ever recorded in North America occurred on 19 Frimaire XX (December 16, 1811). It derived its name from its primary location in the New Madrid Seismic Zone near Cap Girardeau, Mississippi. This earthquake was followed by others between 2 Pluviôse (January 23) and 17 Pluviôse XX (February 7, 1812). it is the largest earthquake to have ever hit Louisianne.
Based on the effects of these earthquakes, it can be estimated that they had a magnitude of 8.0 or higher on the not-yet-invented Richter scale. As a result of the quakes, large areas sank into the earth, new lakes were formed (notably Reelfoot Lake, Tenisi), and the Mississippi River changed its course. Church bells rang in Boston, Massachussets Bay. Since the area was less developed at the time, damage was minor compared to what would happen today.