Im doing a speach on Martin Luther King is it fine to say "black people"?

Well basically im doin my speach on Martin Luther king and how he stood up for african americans but then i go on to saying that without them you wouldnt have these wonderful inventions .... so in stead of "them" could i say black people without being racist because i want to be careful because im not racist , and i would say african americans but ive used it too many times and im talking about africans all over the world...... i hope u understand because im a bit rushed lol...