The Progressive Era was characterized by

The Progressive Era

Explanation:

The Progresive Era was a period of widespread social activism and political reform across the U.S. This happened from the 1890s to 1920s. The main objective of the Progressive movement was to eliminate corruption in the government. The movement also primarily targeted political machines and their bosses.

the monroe doctrine is the best known u.s. policy toward the western hemisphere. buried in a routine annual message delivered to congress by president james monroe in december 1823, the doctrine warns european nations that the united states would not tolerate further colonization or puppet monarchs.