Hi, while you're waiting for people to weigh in, you may be interested in these
FAQ section Historians' views of Howard Zinn's "A People's History of the United States"
/u/CharlieNWilson tackles a few specific sections in Are there any credible books similar to "A People's History of the United States" that are widely endorsed by the historian community? What are some examples of major flaws, misinformation, bias etc contained within its chapters?
/u/Dranton in Zinn's 'A People's History'.
several users give their opinion in What is your opinion on Howard Zinn's A People's History of the United States?