1900s-1920s: Progressive Era & World War I

1901

Theodore Roosevelt becomes president

1906

Pure Food and Drug Act and Meat Inspection Act passed, establishing federal regulations to ensure safety and quality of food and medicine

1913

16th & 17th Amendments; 16th authorized Congress to levy a tax on incomes, 17th shifted power of electing US senators from state to the people of each state

1917

The United States enters World War I, marking a significant shift in American foreign policy and involvement in global conflicts

1918

World War I ends

1919

The Treaty of Versailles is signed, formally ending World War I and imposing heavy reparations and territorial losses on Germany

18th Amendment; prohibition of alcohol manufacture, transportation, and sales

1920

The 19th Amendment is ratified, granting women the right to vote in the United States.

1924

National Origins Act; established a quota system for immigration based on national origin