The Mississippi River Valley contains many interesting geologic stories, perhaps none more mysterious and potentially dangerous than that of the New Madrid seismic zone earthquakes. Here, deep within the North American plate, the central Mississippi River Valley was lit up by at least three major earthquakes during the winter of 1811–1812. Perhaps we could ignore this if it had been a single sequence, but the paleoseismic record tells us that there have also been four prehistoric earthquake sequences within the past 2,600 yr. In this book we travel through time to see how the central Mississippi Valley region developed. Since the earthquakes are occurring on deep basement faults, it is only fitting to start in deep Precambrian time and work our way forward in our quest to better understand the geologic framework of this intra-plate seismic zone. Are more earthquakes coming? It is my hope that this book will stimulate readers to pursue this and many other geologic problems in the Mississippi River Valley.