Is Racism against African Americans still a problem in the USA?

I am from Australia and have never been to America and I don't have any clue about this.

I have read people's comments on different posts about other stuff and have noticed that many say/think/imply racism against African Americans is still a big issue today?

I am curious I thought everyone had grown up and got over the whole " different skin colour" thing.

So is it still an issue? If it is why? What reason would anyone have to still be racist in today's society?

I hope that makes sense I suck at explaining myself. If you have any questions just comment and I will answer.