He fought for Washington, served with Lincoln, witnessed Bunker Hill, and sounded the clarion against slavery on the eve of the Civil War. He negotiated an end to the War of 1812, engineered the annexation of Florida, and won the Supreme Court decision that freed the African captives of La Amistad. He served his nation as minister to six countries, secretary of state, senator, congressman, and president. In this masterful biography, Harlow Giles Unger...