This is the general rule regarding the interaction between whites and blacks in America. There are exceptions, of course, but this is the pattern.
This separation is the burden we carry from the origin of our Republic. Though we see ourselves as a "City on the Hill," an inspiration to ourselves and to the world, our beginning was marred by the original sin of slavery, which we (or some of our forebears) caused to bring to America.
When we observe on television the tragic scenes in Ferguson, Missouri, we get a idea of just how damaged our society is: what we see, in large part, is a black underclass living for the most part apart.
We must come to recognize this original sin in our society and develop a consciousness that this was indeed how we began. We cannot treat blacks as an unwanted population as we (or some of us) had them brought over here.
We need to take more responsibility for what was done in the past in our country. Slavery was not just a "peculiar institution," as some in antebellum America brushed it away. It is our responsibility, as a result of this stain at the creation, to make things better and to come to the realization that we can do more -- much more -- to improve the situation.