The Progressive Era Progressivism in the United States took place in the period between the Spanish-American War and the entry of the United States into the great World War. It was a time for change in America in all walks of life, as well as a time for reform. It was marked by Theodore Roosevelt's 7 and a half years in office, the Rough Rider put it upon himself to make the first strides towards reform. These reforms included the cracking down on illegal monopolies and so forth. During this era large cities transformed into large metropolises, small towns into large cities and new towns sprang up nearly everywhere. Reforms also includ