Fun!

That series of earthquakes (1811-12) is said to have shaken bells in church steeples as far away as Boston and toppled chimneys in Maine, and it changed the course of a significant part of the Mississippi River. However, there is no way to verify the exact magnitude of any of those quakes. Some estimates have the magnitude as low as the 7's, but considering the extent of the intense seismic motions, and the shifting of a large segment of the Mississippi River, 7, or even 8, seems very low-ball to me. And I say this as someone who has experienced earthquakes of 7+ magnitude from 100-200 miles away.

My understanding was the New Madrid was the most powerful one known in the US.

and that's what we were always taught.

Reports were that people thought the gates of Hell had been opened.

"where you stand, depends upon where you sit" one supposes.

ie, most powerful earthquakes centered on the US

It was very very impressive.

Wow. Details??