Self-gain, partisan loyalty, and corruption characterized politics after the Civil War at a time when United States became the world's leading industrial power. Voters divided generally along ethnic, religious, and sectional lines. Republicans controlled the White House during most of these years, while party control of Congress remained divided, with the Republicans usually holding the Senate and Democrats the House. ‘Gilded Age frustration and the Progressive response, 1877–1918’ outlines the emergence of a Progressive movement in the twentieth century—first under President Theodore Roosevelt and then later Woodrow Wilson—which strengthened the executive office, enlarged federal power, and marked the beginnings of the regulatory administrative state. This period of progressive reform lasted until America entered the First World War in 1917.