There was less need for workers on farms since there was devices that could do it for free so many people went to cities and worked in factories which gave them a job and also caused cities to explode with population
Explanation:
Their existence was peaceful, and depended on primitive farming of cultivated plants such as corn, beans, squash and cotton. Their diet also included wild berries, nuts, with very limited hunting. During this time, the Anasazi lived in caves which provided them with shelter.
Africa was stripped of many resources by the Europeans