I might suggest The Correspondence of Mr Justice Holmes and Sir Frederick Pollock, 1874-1932: Holmes-Pollock Letters. This is a collections of letters between two men who started out so alike, then followed such separate paths, though Holmes always quietly yearned for the path followed by Pollock. This collection reveals much about America as Holmes sat on the Supreme Court during very formative times, including World War I. It could be followed by Holmes's biography, such as the title Honorable Justice: The Life of Oliver Wendell Holmes. I might also suggest The Bottom Billion by Paul Collier. It explains the poverty cycle of the poorest of the world's underdeveloped countries.