But, um, those aren't the only People in the United States. Far from it.
The idea is that "the people" connotes the working or middle class, or the everyday joe-shmo. It is a perspective shift. Yes, Rockefeller was a person too, but knowing Zinn's perspective and reading the book I think it becomes clear what he means when he says "people's history."
I am aware that Zinn was well regarded among a lot of people who got their academic training in history thirty or forty years ago, and I've read a few excerpts from the book, but never anything that struck me as particularly notable one way or the other. It's certainly not enough to form an opinion on him, and my experience with American historiography is low to nonexistent on anything approaching a level that would permit me to feel comfortable commenting.
On the topic of objectivity, I commented in the previous thread and was summarily ignored:
Objectivity is only desirable to the point of actually having facts straight, not the opinions one draws from them. Even the choice of facts destroys any presumption of objectivity. There are a near-infinite amount of known facts about many events in modern history, and it is impossible to include them all; the historian must make judgments as to pertinence, and therefore by necessity injects subjectivity. But this subjectivity is desirable, because otherwise we would be left with nothing but the vast ocean of sources and no filter, no way to make sense of any of it. So claiming that Zinn is a poor historian because he does not include all of the facts is silly, because he cannot have done anyway. And the fact that Zinn admits to his lack of objectivity - like virtually every decent historian who has commented on historiography in the past eight decades or so - means that he is at least self-aware enough to be potentially worth a read.
I would, however, think that Zinn's book is not particularly useful on subjects that don't directly deal with the history of activism in American society; it would be like citing John Lewis Gaddis on Turkish history when he offhandedly mentions factoids about the Straits crisis of the late forties in his Cold War writings. If you slavishly employ Zinn's books as catchall references without employing other works, especially more pertinent ones, then you miss the point and the criticism of employing grossly biased sources becomes a relevant one.
I read your first comment, and I read this comment, and as before, I agree with you. My issue is more with those who dismiss Zinn outright rather than those who look to both Zinn and other sources for their particular historical record.