U.S. Imperialism and Foreign Policy in the Late 1800s–Early 1900s

Rev. Josiah Strong

Protestant minister and Social Gospel writer who argued Anglo-Saxons had a duty to spread Christianity and 'civilization,' helping justify late-1800s U.S. expansion and imperialism.

Alfred Thayer Mahan

Naval strategist who argued that national greatness required sea power (a strong navy, coaling stations, and overseas bases), pushing the U.S. toward imperial expansion and a modern navy.

Monroe Doctrine

1823 policy warning European powers not to colonize or interfere in the Western Hemisphere; later used to justify broader U.S. influence in Latin America.

Queen Liliuokalani

Last monarch of Hawaiʻi; overthrown in 1893 by American planters/business interests, leading to U.S. control and eventual annexation.

Gen. 'Butcher' Weyler

Spanish general in Cuba who used 'reconcentration' camps to isolate rebels; his brutality fueled U.S. outrage and pro-war sentiment.

De Lome Letter (Feb. 1898)

Private Spanish diplomat letter insulting President McKinley; published in U.S. newspapers and increased anti-Spanish anger.

'Remember the Maine!' (Feb. 1898)

Slogan after the U.S.S. Maine exploded in Havana Harbor; used to rally support for war with Spain.

Teller Amendment

U.S. promise (1898) that it would not annex Cuba after defeating Spain; aimed to present the war as liberation, not conquest.

Commodore George Dewey

U.S. naval commander who destroyed the Spanish fleet in Manila Bay (1898), giving the U.S. control in the Philippines.

Emilio Aguinaldo

Filipino nationalist leader who fought Spain and then resisted U.S. rule in the Philippine-American War.

Hawaiian annexation (July 1898)

U.S. annexed Hawaiʻi (Newlands Resolution), gaining a key Pacific naval/coaling base (Pearl Harbor area) during the era of expansion.

Gen. William Shafter

U.S. commander in Cuba during the Spanish-American War; led the campaign that ended with Spanish defeat near Santiago.

The Rough Riders

Volunteer cavalry regiment led by Theodore Roosevelt; became a symbol of American vigor and war enthusiasm.

Col. Leonard Wood

U.S. Army officer (close to Roosevelt) who helped lead Rough Riders; later governed Cuba and became a prominent military figure.

Santiago (July 1898)

Major battles around Santiago de Cuba where U.S. forces and navy defeated Spain, leading to Spanish surrender in Cuba.

U.S.S. Oregon

U.S. battleship whose long trip from the Pacific to the Caribbean highlighted the need for a canal and stronger naval readiness.

Anti-Imperialist League

Organization opposing U.S. annexation of overseas territories (especially the Philippines), arguing imperialism violated American ideals and dragged the U.S. into foreign conflicts.

Foraker Act (1900)

Established a U.S. civilian government in Puerto Rico; made Puerto Rico an unincorporated territory under U.S. control.

Insular Cases (1901)

Supreme Court rulings stating the Constitution did not automatically apply fully to all U.S. territories; supported the idea of 'unincorporated territories.'

Dr. Walter Reed

Army physician who proved yellow fever was spread by mosquitoes, enabling effective public-health measures (critical for Cuba and later the Panama Canal Zone).

Platt Amendment

Conditions placed on Cuba (1901) for ending U.S. occupation: limited Cuban treaty-making, allowed U.S. intervention, and required Cuba to lease naval bases.

Guantanamo Bay

U.S. naval base in Cuba obtained through the Platt Amendment arrangements; symbol of ongoing U.S. influence in Cuba.

John Hay

U.S. Secretary of State under McKinley and Roosevelt; promoted Open Door policy and helped negotiate key canal-era treaties.

Open Door Policy

Hay's policy calling for equal trading rights in China and preservation of China's territorial integrity; aimed to protect U.S. economic access without formal colonization.

Boxer Rebellion (1900)

Anti-foreign uprising in China; U.S. joined an international force to suppress it, then reinforced Open Door principles.

Clayton-Bulwer Treaty (1850)

U.S.-Britain agreement that neither would control a Central American canal alone; later revised so the U.S. could build/control a canal.

Hay-Pauncefote Treaty (1901)

U.S.-Britain treaty that replaced Clayton-Bulwer and allowed the U.S. to build and control a canal.

Hay/Bunau-Varilla Treaty (1903)

Agreement granting the U.S. rights to build and control the Panama Canal Zone; negotiated with Panama's representatives after independence.

Panamanian Revolution (1903)

Panama's break from Colombia, supported by U.S. naval presence; enabled U.S. canal construction.

Col. George Washington Goethals

U.S. Army engineer who supervised the canal's construction as chief engineer, getting the project completed.

Col. William Gorgas

Led sanitation/anti-mosquito campaigns in Panama, controlling yellow fever and malaria and making canal construction possible.

Roosevelt Corollary

Addition to the Monroe Doctrine (1904) asserting the U.S. could intervene in Latin American nations to prevent European involvement and stabilize debts.

Dominican Intervention (1905)

U.S. took control of Dominican customs/revenues to manage debt and prevent European intervention; example of the Roosevelt Corollary in action.

Cuban Intervention (1906)

U.S. reoccupied Cuba during political instability, using Platt Amendment authority; showed Cuba's limited sovereignty.

Russo-Japanese War (1904-05)

War over influence in Manchuria/Korea; Japan's victory signaled its rise as a major power and affected U.S. Pacific strategy.

Portsmouth Conference (1905)

Peace negotiations mediated by Theodore Roosevelt ending the Russo-Japanese War; Roosevelt won the Nobel Peace Prize.

Gentlemen's Agreement (1908)

Informal U.S.-Japan deal: Japan limited emigration of laborers to the U.S.; U.S. eased some segregation pressures (like San Francisco school issues).

Great White Fleet (1907)

Roosevelt sent a modern U.S. battle fleet on a world tour to demonstrate U.S. naval power, especially to Japan.

Root-Takahira Agreement (1908)

U.S.-Japan agreement to respect each other's Pacific possessions and support the Open Door in China, easing tensions temporarily.