As the child of African immigrants, and also attending one of the Ivy League schools mentioned in this article, I find this article interesting, though feel its not entirely accurate or fair on a few points. Please do not view the following as attacks, but instead as my thoughts on certain things your presented.
1) To say that I do better is because I have a will that has not been quashed by decades of oppression is simply not true. First, that underscores decades of civil war, unrest, oppression, and turmoil in certain African countries that some immigrants have faced. As far as in America, the color of my skin is black. I still find the same challenges I'm sure you find. Maybe my ancestor was not a slave (in the US), but is that really the reason why one cannot get into an Ivy League school, for example?
2) Also, should the fact that one's ancestor was a slave be more of a reason that one should be admitted into an Ivy League school. I am an American citizen. No less or more than the next person. Please do not decide that you represent a more diverse America because your ancestors were oppressed in America. And, as an American citizen, those ancestors of yours are my legacy as well. However, there are people who constantly say that I am Black because of the color of my skin, that I am not Black because my ancestors were never slaves, that I am not African-American because I was not born in Africa.
3) I don't think its fair to say that the reason African immigrants succeed is only because they are financially affluent. Ask yourself, where did they get all this money from? Do you think the financial and economic conditions in Nigeria are really all that better when compared to America? If so, why leave Nigeria for an American degree and life? I only say so because my parents were not financially supported.
4) From a statistics standpoint, its neither completely valid nor sound to compare median incomes in this manner. The data for Nigerian Median income is a smaller population size. The population size for African Americans is much larger, and would also include data from the Nigerian Median income as well, since most of them are US citizens and are therefore African-American/Black. I would naturally expect a smaller median for a larger population size, especially when the smaller population is included within the larger one.