"A Peoples History of the United States" by Howard Zinn should be read by anyone interested in finding out how the US got to be what it is.
James Carroll has written a very thoughtful history of the US military since WWII. The book is "House of War" and his view is that of an insider, to some extent. His father was the first head of the Defence Intelligence Agency, a body formed by JFK, I believe, to do a job the CIA failed at. He was particularly disturbed by the nuclear threat and the book details the efforts to limit this but also the massive buildup of these weapons.
I mentioned Morris Berman's "Dark Ages America". A good study except for one chapter which I found difficult to follow.
I'm part way through a very interesting little volume by a guy named John Tirman, executive director of MIT's Center for International Studies. The book is "100 Ways America is Screwing Up The World". Well written, pungent and it covers a lot of ground in its 258 pages.
Carroll's book deals a lot with the Cold War. This topic has been appropriated by the well known US historian John Lewis Gaddis and he has written extensively on it. "We Know Now" purports to include a lot of new material released from the former USSR and this appears to have modified Gaddis' thinking, at least slightly. He has followed up with a new work, I think called "Cold War" which is rather brief and reads like Readers Digest. The tone is almost frivolous and, in my view, inappropriate for the material. Several writers are now dismissing Gaddis as a serious historian. A much better, although very detailed Cold War history, is that of the British Historian Hugh Thomas-"Armed Truce". It was written in 1986, however, so a lot of new material is now available that it did not have access to.
I have George F Kennan's "Memoirs 1925-1950". Although I have not read it through, many specific items I found excellent. He was the most knowledgeable American on the Soviet Union, and that by far. Unfortunately he was discarded by the War Machine and lost his influence.
A book which has too much detail but is, nevertheless, a fascinating study of a real bastard is the work by Jung Chang and Jon Halliday- Mao, "The Unknown Story".