Andrew Mellon rose to become one of America's greatest financiers. Despite painful shyness and personal misery - his loveless marriage ended in scandalous divorce - he built a mighty and diverse fortune, tracking America's course to global economic supremacy. As treasury secretary under Harding, Coolidge and Hoover, he made the federal government run like a business - prefiguring the public official as CEO - and won credit for the Roaring Twenties. But Mellon would stay on too long: blamed for the Great Depression, he eventually found himself a broken icon, his every fiscal assumption overthrown by the New Deal. Prosecuted for tax evasion, Mellon would not abandon his last dream, to make a great gift to America; but he died before his National Gallery of Art was realized. David Cannadine is one of our greatest historians and Mellon is his masterpiece.