Depends on what American's you are talking to.

For most Americans, he was a heroic sports figure. For the repressed "Black Islamic" people he was inspiring, because he was a voice. As a Parkinson's survivor, he moves on with his life which is an inspiration to those who want to throw in the towel. As a symbol of American integrity and values, you'll get some debate but the majority will say he was an true Ambassador just the same.

In case you are still wondering the answer is Yes! he is an American Hero, but not to all Americans.