Why did the south want and need slavery?

The south needed a slavery for low-cost Workforce from Africa and they want it for the same reason: this way the economy of the south (focused on agriculture in plantations) can increase, by playing less and earning more

where is the picture

so they can differentiate themselves from others as they saw themselves as the superior race. the star was basically a symbol that meant you are a less of a person than i am because of my race. the star was also degrading for those who had to wear it because they were aware of this and the nazis used the notion to make them feel less like a person.