Some US Geological History:

December 16, 1811, marked the beginning of the massive New Madrid Earthquake Series, the most powerful earthquakes in U.S. history, centered near New Madrid, Missouri, which caused immense ground shaking, river changes (even making the Mississippi flow backward!), created new lakes (like Reelfoot Lake), and were felt hundreds of miles away, changing the landscape and demonstrating the powerful, yet sparsely populated, frontier's vulnerability. 

Key Details of the 1811-1812 New Madrid Earthquakes:

Magnitude: Several major quakes (estimated M 7.0-7.7+) occurred, with a series of powerful shocks from December 1811 to February 1812, followed by thousands of aftershocks.

Impact: Land was uplifted and sunken, fissures opened, landslides occurred, and the Mississippi River's course was temporarily reversed.

Perceptibility: The quakes were felt across the eastern U.S., from New Orleans to New York.

Damage: The frontier region was sparsely populated, so few lives were lost, but the shaking destroyed cabins and toppled chimneys in distant towns like St. Louis and Cincinnati.

Legacy: The event created the New Madrid Seismic Zone (NMSZ) and is still considered the largest earthquake sequence in U.S. history.