https://en.wikipedia.org/wiki/1811%E2%80%9312_New_Madrid_earthquakes

1811–12 New Madrid earthquakes

"New forecasts estimate a 7 to 10 percent chance, in the next 50 years, of a repeat of a major earthquake like those that occurred in 1811–1812, which likely had magnitudes of between 7.6 and 8.0.  There is a 25 to 40 percent chance, in a 50-year time span, of a magnitude 6.0 or greater earthquake.^"

^{New Madrid fault and earthquake-prone region considered at high risk today}

4000 earthquake reports since 1974