The American racial question

What happens with the American racial question? The world is dominated by white men. In America could not be different. The white americans inherited a european vision about races. After various fights (Martin Luther King Jr. and others), after Barack Obama was President, the black americans finally can be citizens in all States. And latinos... What is noticeable is that there is no mixture between races, in other words, marriages between races. Each one stays in your ethnic group. The mixture that exists is few (reminder, there are blacks and latinos racists). In countries how Brazil to racial mixture is secular. Whites, blacks and indians mix for centuries (even though the ruling class be composed for whites). Instead of talking afro-americans, latinos and whites, should be said: we are all americans.