The largest earthquakes in the history of the United States were produced by the New Madrid Seismic Zone in 1811 and 1812. 
These were followed by a steady stream of tremors of varying intensity.
The ground rolled and the Mississippi River foamed up like a boiling caldron. The atmosphere was filled with suffocating sulphuric fumes. Many people fled the area and never returned.
It is said that the Mississippi River ran backwards for a time, but that perception was probably due to the river sloshing back and forth. The 20-mile-long Reelfoot Lake in northwest Tennessee, now an outdoorsman’s paradise, was formed as a result of the earthquake.
Early settlers in Missouri built their homes near water, not only because they needed water for themselves and their livestock, but because the soil was generally superior, and the rivers provided an efficient means of transportation for shipping and receiving goods.
The bluffs overlooking the Mississippi River had the additional advantage of being above the flood plain.
Settlement in the New Madrid region began right after the Revolutionary War ended. When Missouri was still under the Spanish Regime, all boats on the Mississippi River were required to stop at New Madrid to have their cargo inspected.
In the spring of the year, as many as 100 boats stopped at New Madrid in a single day. By 1804, however, the population was diminishing and the river bank was constantly caving in, taking buildings with it.
A great deal of misinformation has been published on both the town and the earthquakes. There were no brick, stone, or frame homes in New Madrid at the time of the earthquake. Everything was log.
There were no brick chimneys; they were built of mud reinforced with sticks and daubed with more mud. John Bradbury, who stopped in New Madrid two days before the earthquakes began, wrote that the town consisted of but a few straggling houses and two “indifferently-furnished stores.”
