in U.S. history, a broadly based reform movement that reached its height early in the 20th cent. In the decades following the Civil War rapid industrialization transformed the United States. A national rail system was completed; agriculture was mechanized; the factory system spread; and cities grew rapidly in size and number. The progressive movement arose as a response to the vast changes brought by industrialization. Progressivism began in the cities, where the problems were most acute. Dedicated men and women of middle-class background moved into the slums and established settlement houses. Led by women such as Jane Addams in Chicago and Lillian Wald in New York City, they hoped to improve slum life through programs of self-help. Other reformers attacked corruption in municipal government; they formed nonpartisan leagues to defeat the entrenched bosses and their political machines. During the 1890s, reform mayors such as Hazen Pingree in Detroit, Samuel Jones in Toledo, and James…