It is seen as a crime, just not as an official sense. If you mean as a crime against the law, racism against Africans in which causes the defendant to be hurt in anyway is against the law. (Given that the non-defendent does not have a valid reason for their actions) As for the past, the people who were for slavery etc. are dead and America is kinda on a "forgive and forget, and let's never think about anything like this again to avoid issues" basis.
Slavery? For a country to be getting away with such crime should be consider against the International Laws. Slavery is a crime against Humanity and its also consider as 'BULLYING'. Help stop the BULLYING TODAY.The world can be a better place. Amen.
I'm sure most people consider slavery of any kind to be morally criminal. But since the slavery of black Africans is nothing more than past history, what does it matter now? And were not the black Africans who sold their own people to the slavers to begin with as equally guilty? Are you looking for someone to blame "now"? The issue is long gone.
From accounts I have read there was plenty of effort on part of tribal chieftains to make sure that a ready supply of slaves were available back in the days of slavery. This is point that does not get enough discussion in history books.