Institutionalization of Jim Crowe laws and increased availability of manufacturing jobs.
Explanation:
After the return to power of white democratic leaders in the South during late XIX century, local government encated laws to limit the political participation of African-Americans and also to segregate them. At the same time, Northern and Western states opened a number of job positions, specially in the steelmaker industry, where this population saw a new opportunity to leave behind discrimination in the South.
