The President who gave them hell, withstood the heat in the kitchen, and knew where the buck stopped speaks out on subjects from Geronimo to the two-party system in his incomparable, no-nonsense style. 30,000 first printing. $25,000 ad promo.
This is not the only collection of Harry Truman's candid comments on various subjects after he left the presidency, but it's the one I found. That the book is a quick read reflects well on the accuracy of Truman's legend as a "plain-speaking" man.
The opinions demonstrate that Truman, though candid, is intelligent but not unusually deep, perceptive or observant; not really possessed of any revelatory insights that other observers of his time didn't figure out. Therefore, Truman's opinions are much more valuable for what they teach about Truman himself, whom I am not deeply familiar with other than knowing the widely known information about his presidency.
It will help to be familiar with the presidency and character of Andrew Jackson, because it becomes obvious that Truman's political and social views are absolutely Jacksonian--one could gather that even if the comments hadn't praised Jackson. Besides complaining about "economic royalists," Truman also earnestly insisted on the primacy of the executive branch, and was frankly dismissive of Congress (and had nothing to say about the judiciary). Also dismissive and somewhat contemptuous of past presidents who believed their duty was only to enforce the laws passed by Congress. This is pretty consistent with everything I've ever read or heard about Truman's attitude and behavior as president.
Notably, Truman never indicates any special reverence for his boss Franklin Roosevelt, and doesn't have nearly as much to say about Roosevelt as about Washington, Jefferson, or Lincoln.
The book is interesting, but nothing I had to keep; and it's going into the library for-sale bin.