Key Figures of U.S. Imperialism (1890s–1920s)

American imperialism at the turn of the 20th century was driven by politicians, strategists, and businessmen who expanded U.S. power across the Pacific and Caribbean.

Political Leaders

• William McKinley (Pres. 1897–1901) – Spanish-American War; annexed Philippines, Puerto Rico, Guam; Hawaii.
• Theodore Roosevelt (Pres. 1901–1909) – "Big Stick" diplomacy; Panama Canal, Roosevelt Corollary, Great White Fleet, Nobel Peace Prize (Russo-Japanese War).
• Woodrow Wilson (Pres. 1913–1921) – "Missionary diplomacy"; interventions in Mexico, Haiti, Dominican Republic, Nicaragua; WWI entry; League of Nations.

Intellectuals & Strategists

• Alfred Thayer Mahan – Naval historian; The Influence of Sea Power Upon History (1890) argued navy = greatness; influenced TR, Kaiser, Japanese leaders.
• Brooks Adams – Historian; The Law of Civilization and Decay; predicted U.S. global dominance.

Business & Empire Builders

• Cecil Rhodes (British) – Cape to Cairo vision; De Beers; Rhodesia; influenced Anglo-American elite circles.
• Henry Cabot Lodge – Senator; architect of imperialist legislation; Lodge Corollary (1912) to Monroe Doctrine.
• John Hay – Secretary of State (McKinley, TR); Open Door Policy (China); Panama Canal treaty.

Anti-Imperialists (Opposition)

• Mark Twain, Andrew Carnegie, William Jennings Bryan, Jane Addams, Moorfield Storey – Anti-Imperialist League (1898); opposed Philippines annexation.

These figures shaped the debate and execution of America's transition to world power.