The Effects of Progressivism in Government The period of time between the Spanish-American War and World War I is known as the Progressive Era. It was a period marked by idealism, reform, and significant economic growth. Progressivism was a movement designed to correct the abuses which reformers felt had crept into American society and government, as a result of industrialization and urbanization. Progressivism was the outcome of a number of forces in American life. The reform spirit of the 1880's and 1890's was still strong, despite the collapse of the Populist Party after the election