Since I was a kid. I had this series by Ballantine Books about the history of World Wars I and II. In my 20s, it was the Vietnam War literature of novelists like Tim O'Brien, Philip Caputo, and Tobias Wolff, and then nonfiction such as "A Bright Shining Lie" by Neil Sheehan and "The Best and Brightest" by David Halberstam . Those are the two best histories of Vietnam.