On this day in 1811, the New Madrid earthquake struck the eastern United States. The quake and its many aftershocks were so powerful that an 18-mile-long lake was created, the Mississippi River ran backward, and entire towns were wiped from the map. The event occurred during the passing of the Tecumseh comet, named for Chief Tecumseh. Native Americans heralded it as a prophetic sign to follow him in his war against the white settlers.