This is one of the two best books I've found. Has lots of Information. The other book I recommend is U.S. Navy Aircraft 1921-1941/U.S. Marine Corps Aircraft 1941-1959 by William T. Larkins which is given credit in this book. These are the only two books I'd have if I could afford only two books.
A good over view of American Military Aircraft from the earliest days to the beginnings of the jet era. Covering such a large field it is not possible to include comprehensive detail but for me it was an introduction to some types I had never heard of. An interesting and worthwhile addition to airplane libraries.