This is a lucid and thematic exploration of America's emergence as a global superpower in the first half of the 20th century. Involvement in the two world wars was central to the process and the roles played by two of America's most influential presidents, Woodrow Wilson and Franklin Roosevelt, are analyzed within this context. Key events of the period such as the Versailles Peace conference, Pearl Harbor and the bombing of Hiroshima are examined from an American perspective. The author also assesses American isolationism between the wars and US-Japanese relations from 1919 to 1941. The narrative incorporates research and a selection of source-based and essay questions.