1891
Populist Party forms

1899
Aguinaldo leads Filipino Insurrection

John Hay writes First Open Door Note

1900
Congress passes Gold Standard Act

Congress passes Foraker Act

U.S. sends troops to China to suppress Boxer Rebellion

Hay drafts Second Open Door Note

McKinley is reelected

1901
McKinley is assassinated; Theodore Roosevelt becomes president

Hay-Pauncefote Treaty

U.S. Steel Corporation forms

Insular Cases decided

Congress passes Platt Amendment

1902
Colombia rejects canal treaty

Anthracite Strike

Congress passes Newlands Act

1903
U.S. backs Panamanian revolt against Colombia

Hay–Bunau-Varilla Treaty

Congress passes Elkins Act

1904
Roosevelt issues Roosevelt Corollary to the Monroe Doctrine

Construction on Panama Canal begins

Lincoln Steffens publishes The Shame of the Cities

Roosevelt creates U.S. Forest Service

Northern Securities decision

Industrial Workers of the World forms

Theodore Roosevelt is elected president

1905
United States invades Dominican Republic

Roosevelt negotiates peace to end Russo-Japanese War

1906
San Francisco bans Japanese students from public schools

Algeciras Conference

United States invades Cuba

Upton Sinclair publishes The Jungle

Congress passes Pure Food and Drug Act, Meat Inspection Act, and Hepburn Act

1907
Roosevelt sends Great White Fleet on world tour

Roosevelt strikes “Gentlemen’s Agreement” with Japan

“Roosevelt Panic” hits

1908
Root-Takahira Agreement

Muller v. Oregon case

William Howard Taft is elected president

1909
Congress passes Payne-Aldrich Tariff

New York City garment worker protest

1910
Ballinger-Pinchot Affair

1911
Triangle Shirtwaist Company fire

Standard Oil anti-trust case

U.S. Steel Corporation anti-trust case

1912
Taft and Roosevelt split Republican Party

Woodrow Wilson is elected president

1913
Sixteenth and Seventeenth Amendments are ratified

Congress passes Federal Reserve Act and Underwood Tariff

1914
Panama Canal is completed

Congress passes Clayton Anti-Trust Act, establishes Federal Trade Commission

United States occupies Vera Cruz, Mexico

1915
Congress passes La Follette Seaman’s Act

United States invades Haiti

1916
Congress passes Workingmen’s Compensation Act, Federal Farm Loan Act, Warehouse Act, Adamson Act, and Jones Act

Pancho Villa attacks New Mexico

United States invades Dominican Republic

1917
United States buys Virgin Islands