Howard Zinn wrote A People's History of the United States as a counter to the usual histories of the US that focus on presidents, statesmen, and robber barons of the Gilded Age. He covers things we mostly don't learn about in school, including the rise of the Labor movement, native Americans, slaves and post-Civil War freedman, and women.
Also read Smedley Butler's _War is a Racket_ for an early comment on the "Military Industrial Complex".