New Madrid Earthquakes Begin

Date: December 16, 1811 • Location: Portageville, United States

This milestone marked the outbreak and beginning of this historic period, which spanned 1811–1812.

The first two in a series of four severe earthquakes struck the Midwestern United States and made the Mississippi River appear to run backward.

The 1811–1812 New Madrid earthquakes were a series of intense intraplate earthquakes beginning with an initial earthquake of moment magnitude 7.2–8.2 on December 16, 1811, followed by a moment magnitude 7.4 aftershock on the same day. Two additional earthquakes of similar magnitude followed in January and February 1812. They remain the most powerful earthquakes to hit the contiguous United States east of the Rocky Mountains in recorded history. The earthquakes, as well as the seismic zone of their occurrence, were named for the Mississippi River town of New Madrid, then part of the Louisiana Territory and now within the U.S. state of Missouri.