Progressive Era: A period of social activism and political reform in the early 20th century that aimed to address issues caused by industrialization, urbanization, and political corruption.
World War I: A global conflict fought from 1914 to 1918 involving many countries, including the United States, which significantly impacted American society and marked a turning point in world history.
Great Depression: The severe economic downturn that began with the stock market crash of 1929 and lasted throughout much of the 1930s, causing widespread unemployment and hardship for many Americans.