Yes, we white men took slaves from Africa to the Americas. Guess how we got them? We bought them from OTHER AFRICANS. Why do people seem to think that Europeans where the only ones who had slaves? NEXT TO EVERYONE HAD SLAVES, and you, as a white person, have no more need to feel ashamed over historical slavery then every other ethnicity on Earth.
In short, Every race has done evil, every culture has blood on their hands. As a white man, I feel my ethnicity has done a reasonable job of fixing the problems it has caused. There is an Atticus Finch for every Bob Ewell, an Abraham Lincoln for every General Lee. If this is insufficient for you, and you feel guilt regardless of the crimes of other races then that is fine. Let that drive you to even greater heights of tolerance, and work to rout out prejudiced behavior wherever you may find it. But please, don't urinate upon your entire culture, history, and people just because a few of 'em were dicks! And for the love of St. Peter, don't feel you are destined, by the color of your skin, to be just as shallow as your kinsmen! Trust me when I say we, of all the different races, can be better then our past, and more to the point, be better then our present.
PS-I apologize if you don't get the second last reference-It's from Harper Lee's "To Kill a Mockingbird". If you haven't read it, I sugest doing so ASAP. A good book will do wonders to keep your mind of things.