The main reason why there was a massive immigration towards the Sun Belt was because it was unoccupied relatively to the other areas of the US, this meant that new servrices and industries could be developed for the young and flourishing naiton.
Earthquakes and land drifting is caused by the movement/shifting of tectonic plates.
Black codes were restrictive laws designed to limit the freedom of African Americans and ensure their availability as a cheap labor force after slavery was abolished during the Civil War.
