Why is racism so prevalent in the US?

My foreign exchange student friends ask me this a lot. Unfortunately America was found off racism, if you really analyze it. They pass down the hate from generation to generation, and the cycle continues( some break the cycle). I'm not white, but not all white people are racist. It's more common in the south because that's where slavery mainly took place, and some people can't get over themselves enough to realize that this is the 21st century!!!! Nobody can help what race they are!!!Most people here still have a 17th/18th century mentality. And you're right America is kinda at a standstill, they should judge by character not by skin tone...it's amazing how superficial things make people think they are better than somebody else...