African Ameriacn Students in Specian Education Classes

Why is so many Africans American Students placed into Special Education Classes?  I would love to have someone give me a reason why this is so? Does it have to do with lack of properly funding their schools? Or is it due to a lack of quality teachers?  Or does it have to do with the issues where African American students are not giving the basic in early primary schools? Once more I would love to have some input into why this is so.