In the early 20th century, what was the primary cause of the large-scale migration of african americans out of the rural south

Buisness was booming . More and more americans began to be more about consumption of products, so more and more factories were being built. That and the racism and jim crow laws in the south made life diffucult for people of color. 

The preamble explains the reasons  why ben franklin and the other founding fathers  of the constitution made our government a republic. by doing this they also replaced the articles of confederation