Dr. Manhattan gives a long history of the impact of segregation on the changes in fortunes of the New York Yankees and the Boston Red Sox in the 1960's. Incidentally, a number of other teams were also slow to integrate, but these are striking because they are based in areas that fancy themselves as having progressive ideas about race relations.
By now everybody should have heard of the Jackie Robinson story and the integration of baseball. Nobody can question that the man was courageous. Branch Rickey also traditionally gets a lot of credit for this. IMO Robinson deserves his acclaim, but Rickey's contribution is less admirable.
You see, Rickey worked in management. Of course management is interested in getting their labor at the lowest price consistent with acceptable quality. And Rickey saw that there were a lot of highly talented players working cheap in the Negro Leagues. If he could recruit them for his employers of the time, the Dodgers, he could improve the team while simultaneously lowering the payroll. He might have done something good, but it's not as if he had been doing it solely for integration's sake. I'd be interested in seeing comparisons of salaries between black and white players over those early days in conjunction with some of Bill James' sabermetric data to see reasonably objective player values.
If you read books about old-time baseball one of the striking things about it was the hostility of veterans for rookies. The rookies were out to take the veterans' jobs, and vets would bond against them.
Now introduce a bunch of black players to the equation. Now there's even more competition for positions, and this time from experienced players who've been playing for peanuts. The established players would have been hostile under any circumstances, but when the race angle was thrown in also you could expect fireworks.
IMO this points to the real roots of racism - economic competition. If blacks or other minorities truly were inferior there would be no point in discriminating - they'd be kept down all by themselves. But when they were present in numbers sufficient to have significant economic impact, as they were in the American South and in South Africa, whites took measures to impair their economic effectiveness via Jim Crow and apartheid.
If economic competition is in fact the root of racism, it follows that having a good economy is what we can do best to eliminate it. When you're busy, or when you're fighting for your life in a foxhole, you're not likely to get picky about your compatriots.
And in bad times, people are ready to listen to demagogues who tell them that those people who look different really are different.