The Wit and Wisdom of Harry Truman by Ralph Keyes is a pocketbook size anthology that starts with a biography of the president, ends with selected diary entries, and in between divides almost 1000 quotes and anecdotes by topic.
So, under “Children” you can find, “I have found the best way to give advice to your children is to find out what they want and advise them to do it.” Under “Politics,” “I wonder how far Moses would have gone if he’d taken a poll in Egypt?” And on his own presidency, to Adlai Stevenson, “If a knucklehead like me can be president and not do too badly, think what a really educated smart guy like you could do in the job.”