I know the answer is very complex, but I still wonder if there are any events in history that would partly explain why Africa was worse off than countries on other continents. America and India was colonized, so that can't be the only answer considering neither America or India is in as much hardship as most African countries. It can't only be a result of wars, China's economy boomed.
I don't want to discourage new answers, but there are a few older questions in the FAQ that address this post.
What caused Africa to be so poor and corrupt?
Why are former African colonies generally much less developed than former Asian colonies?
Why is Africa not as developed as the other continents besides Antarctica?
Why did all of the other continents develop so much quicker than Africa?