Henry Brooks Adams (February 16, 1838 – March 27, 1918) was an American historian and member of the Adams political family, being descended from two U.S. Presidents.As a young Harvard graduate, he was secretary to his father, Charles Francis Adams, Abraham Lincoln’s ambassador in London, a posting that had much influence on the younger man, both through experience of wartime diplomacy and absorption in English culture, especially the works of John Stuart Mill.