How reliable are Kenneth C. Davis' "Don't Know Much About the Civil War" and Howard Zinn's "A People's History of the United States"?

by b-a-n-a-n-a-s

I'm about 100 pages into "Don't Know Much About the Civil War" and have enjoyed the writing style, but there are times when it seems really casual and perhaps a bit biased (although this is usually when exposing hypocrisy of the justification of slave-owning). I realize this may be Davis' way of making the book more relateable to a wider audience, but it throws me off sometimes. I will be going through Howard Zinn's "A People's History of the United States" after I've finished this one, but wanted to know if there is any in particular I should look out for with these two authors. I always try to be a critical reader but history is something of a new interest and is pretty foreign to me since I was raised with a very biased Christian curriculum (homeschooled).

When_Ducks_Attack

Before anybody else does it, allow me to direct you to the FAQ for the Zinn portion of the question.