Help Me Out

  Can someone help me out here for a second. I'm trying to find out some information on human civilization over the course of time and I'm not finding it.

  You see I was a terrible high school student. I used to make up little time graphs and check off the minutes as a countdown to the end of the class period, so I missed a lot, especially in world history class.

  When was the time in human history when separating people according to race, religion, sex, or wealth ended well for all parties involved? Yes, when did this type of plan end well. Because all I can seem to find is that it never did end well. Some cultures spent decades or even centuries trying to get over such separation. Some never really survived it and collapsed. What did I miss.

  Oh yeah, one more thing, which of the many people who devised such plans are now regarded as wise and brilliant human beings?