Is Rosa Parks really a lone hero, riding away on her bus into the sunset? Certainly she is on the fast track to sainthood. Everyone who is anyone is currently lionizing her as the hero of the battle for civil rights for blacks. Only a few, however, have mentioned that earlier in her famous summer, a pair of unnamed black women had also gotten arrested. And for many years prior to Rosa's last stand, now-anonymous blacks fought and struggled for their right to be treated equally under the law.
So what makes Rosa Parks special? I say nothing much. She was not the first black hero, nor will she be the last one. Rosa Parks the person was clearly a brave person, but Rosa Parks is not just a person at this point. She has become a symbol, standing for many unnamed brave black people, each of them unwilling to accept being unfree in the Land of the Free and The Home of the Brave [black person]. People have a tendancy to personalize groups and movements, turning real people with foibles and faults into symbols. This is, I think, the flip side of our tendency towards bigotry. Just as we praise individuals (Rosa Parks) for the attributes of the group (the many blacks who struggled to be free), we also damn individuals for the (perceived) attributes of the group.
So why were the Jim Crow laws that mandated discrimination necessary? Because the nature of bigotry in a marketplace is a commons. Bigotry can be seen as an expense to a business. No business is well-served by treating potential (black) customers badly. No business is well-served by refusing to hire hard workers simply because of their color. The more any one business indulges itself in bigotry, the less profitable it is, and the more likely a non-bigoted business will be able to out-compete them. Thus, there is a limited amount of bigotry available to anyone.
A Jim Crow law serves to increase the available pool of bigotry by mandating that everyone be bigoted. It would be in a business's interest to cheat on Jim Crow laws and thus earn some extra profit, but such cheating would be highly visible. You can't not notice a black counterman serving white folks.
What finally broke the back of Jim Crow laws was black people refusing to put up with them. They attacked the backbone of businesses, so that businesses were hurt more by Jim Crow laws than they benefitted from idulging their bigotry. In the fourty years since the civil rights struggle was won, bigotry, although still present in American culture, has become unacceptable in polite company. Thus, I don't think that Jim Crow laws could get passed anywhere now.
And that's a good thing.