During the period from 1877-1920, the United States experienced rapid industrialization and urbanization. Many Americans moved to cities where factories provided jobs, though workers often lived in poor conditions. New technologies like the assembly line boosted industrial output but also led to concerns about labor conditions. As cities grew, they faced issues with housing, infrastructure, and political corruption. In response, reform movements gained momentum through muckraking journalism and efforts to empower workers through organized labor and unions.