It's not at all clear how "racial balance" is, either. That's why I asked the above, with a link to the relevant Sequences post.
America has less Europeans than Finland does, and less Asians than Shanghai does, and more Hispanics and Africans than either. Asian Americans and European Americans score better on the PISA than Hispanic Americans or African Americans. I'm using the word "balance" to mean "distribution," not some measure of race relations.
ETA: The table linked by Landsburg has been called into serious question by Evan Soltas [H.T. CronoDAS]. I edited the post to leave only the table to provide context for the comment discussion of its status.
Economist Steve Landsburg has a post [H.T. David Henderson] about the supposed stagnation of median wages in the United States in recent decades. In the linked table median wages have risen for: