Perhaps, but generally speaking most of these hypenated terms only came about in common usage starting in the 1980's, more specifically the mid-1980's. Prior to that I just don't think too many people used the verbage and it just wasn't in print very often.
I'll play devils advocate here. Maybe certain people in certain recent immigrant groups use the hypenation because they think that they are only considered an American when we as Americans find it convenient to deem then so. The rest of the time they are regarded by many Americans to be just sub-class people. This always seems to be the case when our country fall on tragedy or gets involved in a war. We only seem to consider many new immigrant citizens as American when we need them in our armed forces or to stand up for our cause. This was very prevelent and evident during the Civil War and during WWI. When we need them, we tell them "do your part, you are an American damn it"! The rest of the time we always find them being told "go back to your own damn counrty" Am I right?
Another thing to keep in mind with regard to most deep rooted black Americans is that their ancestors did not come to this country by choice my friend. They were taken captive and yanked from their way of life in Africa a few hundred years ago totally against their will.
Now inspite of this I still believe that if someone living here does not want to be an American then they should just go live somewhere else.