More over, we are talking about blacks, a large minority, that in fact, locally had a large majority. There is an economic incentive there; an incentive that doesnt exist for tiny minorities that do not live as concentrated as blacks did (and to some extend still do).
A free market didn't exist then either. My parents spoke of a time when they saw black men hanging from trees in the 40's and 50's and everybody just went about their business and ignored it. There's nothing free about that. A free market is one where your property, and person are not violated, and if they are, there are stiff penalties.
Blacks were not treated equitably under the same laws as other lighter skinned persons. That should have been their beef, not whether someone should serve them the same as everybody else. Similar or identical service shouldn't have been the legal issue. You preach against racism, you don't legalize it.
I hate racism, in fact, I abhor it, but I don't think laws change behaviors and beliefs just cause you write it on a piece of parchment. And besides, the side effects of violating property rights and personal behavior only makes the situation worse. Discrimination punishment is not proportional in its application. Proportionality is always key to equitable law.