I don't know how different Alabama is from Louisiana, but if its similar then they wouldn't have even needed a mandate to accomplish that. Every low income job in almost every town was covered by the local negros because its all they could get hired at, and (unlike the rest of America) there were a lot of blacks to easily cover that.

I still remember the first time I left the Swamps and went to a McDonalds and was greeted by someone with a smile who was actually helpful. I didn't think that was possible, and it genuinely changed my understanding of the world.