I believe that the disrcrimination
that happened to the Arfican American people was purely because of the past. In the old days, there used to be slaves (mostly in southern states, but also all over the world). These slaves were black poor people, they were thought of as someones property rather then a human being. Most of them worked in plantations or in houses where rich white people lived. They lived an extrememly tough life, having to endure many things that most of us wouldnt survive through. They were treated horribly and were even sold at auctions just like you would sell an item.
Although times had changed by the 1900's and most of the slavery around the world had diminsihed. Segregation and discrimination had followed it, which I believe is mainly due to the past and people not wanting to move with the future. For generations this idea that black people were the runts was carved into peoples minds, time is the only thing that could heal this.
Even today many African Americans experience discriminations, although it is not as prevalent. And the thinking of the past has faded into the background, as time and willingness to change have made this possible.