I looked at AOII Maryland's tumblir, and I thought I did see an AA member?
AAs are 12% of the Maryland student population, and Greeks are 15% of the student population. The whole chapter is pretty white, but I did see Asian and Latina members. The one chapter I advise has AA members (St. Joseph's U) but the other does not (U Maine) - but there just aren't that many AA students at Maine. When I read our national magazine, AOII seems like it is very diverse, but I guess it depends on the school.