Not long ago, there was discussion in the United States whether descendants of slaves should be compensated. One argument against this was that these descendants most probably had a better life in the US than they would have in Africa. Some recent research comes to the conclusion that it is rather the descendants in the regions where the slaves came from that should be compensated.
This is not exactly true. I come to this conclusion reading the analysis of Nathan Nunn. Using shipping logs from the slave trade, he constructs a dataset on the ethnic origin of slaves. After matching ethnicities to current countries, he finds that those where more slaves were taken fare worse nowadays. It is fascinating, and disturbing, that the slave trade can still have a significant impact so long after it ended. Why would this be? Maybe from the disruption in the social and government structures that the slave trade induced, which were not unlike civil war as ethnicities chased each other, and even traded their own.
Thus, even if the United States was not a colonizing power in Africa, it carries a special responsibility in aiding those countries that suffered the most from the slave trade. Let us not put all the blame on the colonizers.