Was the United States an empire like the British Empire?

Yes, but not in an identical form. Britain governed a formal empire that covered about 35.5 million km² in 1920. The United States annexed Indigenous lands and overseas territories, especially in 1898, then relied more heavily after 1945 on military bases, alliances, covert intervention, finance and sanctions. Puerto Rico, Guam and American Samoa remain US territories in 2026.

When did the American Empire begin?

There is no single agreed date. Continental settler conquest began in the colonial era and continued after US independence in 1776. Key markers include the Louisiana Purchase in 1803, the Indian Removal Act in 1830, the Mexican Cession of about 1.36 million km² in 1848, and the acquisition of Puerto Rico, Guam and the Philippines in 1898.

How large was the British Empire at its peak?

Historical territorial compilations place the British Empire at about 35.5 million km² in 1920, roughly 24% of Earth’s land. Its recorded population reached about 458 million in 1921. These peaks occurred in different years and should not be merged into one statistic, but together they indicate the scale of formal British rule after the First World War.

How did British and American imperialism differ economically?

Britain used chartered companies, colonial taxation, plantation slavery, imperial preference and sterling finance. The United States used territorial acquisition too, but after 1944 increasingly projected power through dollar finance, corporations, aid, sanctions and the Bretton Woods institutions. Britain more often embedded extraction in colonial administration; Washington more often influenced formally sovereign states through access, dependency and policy pressure.

Why do some historians call US foreign power an empire?

Historians use the term because the United States acquired overseas territories in 1898, suppressed Philippine independence from 1899, maintained unequal territorial citizenship and later shaped governments through military, economic and covert means. The CIA-backed operations against Mohammad Mosaddegh in Iran in 1953 and Jacobo Árbenz in Guatemala in 1954 are frequently cited examples of imperial power without formal annexation.

American Empire vs British Empire: A Comparison

Compare American and British imperial power: territorial rule, wars, finance, bases, racial hierarchy, decolonisation and continuing global influence.

The British Empire chiefly formalised overseas domination through colonies and imperial administration, whereas the American Empire has relied more heavily on annexation, military bases, client governments and economic leverage; both converted unequal power into strategic, commercial and racial advantage.

This comparison treats “empire” as a structure of power, not merely a legal title. Britain openly governed vast colonial populations; the United States denied being an empire while dispossessing Indigenous nations, acquiring overseas territories and repeatedly determining other states’ political and economic choices. See the archive hubs on the American Empire and British Empire.

Key takeaways

Britain generally ruled colonies directly, while the United States increasingly exercised imperial power through bases, finance, alliances, sanctions and selected interventions.
Both empires joined state violence to private accumulation and used racial hierarchy to limit sovereignty, citizenship, landholding and freedom of movement.
The British Empire covered about 35.5 million square kilometres in 1920 and governed about 458 million people in 1921.
American territorial empire became explicit in 1898, but after 1945 its widest influence usually operated without annexation or colonial ministries.
Comparing the empires clarifies shared structures without treating British colonial administration and American informal predominance as identical systems.

Comparison at a glance

Dimension	American Empire	British Empire
Formation	Continental settler expansion followed by overseas annexation and informal control	Maritime commerce, chartered companies, conquest, settlement and colonial government
Landmark expansion	Louisiana Purchase in 1803; Mexican Cession in 1848; overseas acquisitions in 1898	East India Company rule expanded after Plassey in 1757; Crown rule in India began in 1858
Maximum territorial scale	Sovereign territory and dependencies never approached Britain’s formal extent; global reach later centred on bases and alliances	Covered about 35.5 million km² in 1920, or roughly 24% of Earth’s land, according to historical territorial compilations
Subjects and citizens	Indigenous peoples, annexed Mexicans, Filipinos, Puerto Ricans, Guamanians, Hawaiians and others faced unequal status	Hundreds of millions lived as colonial subjects rather than equal citizens; the 1921 imperial population was about 458 million
Governing form	States, incorporated and unincorporated territories, occupations, protectorates, compacts and client regimes	Crown colonies, dominions, protectorates, mandates, princely states and company territories
Economic instruments	Dollar finance, corporations, trade access, aid, sanctions and institutions shaped after 1944	Chartered monopolies, land revenue, plantation slavery, sterling finance and imperial preference
Military architecture	A worldwide network of installations: the US Department of Defense reported 514 overseas sites in its 2018 Base Structure Report	Naval stations, coaling ports, garrisons and fortified chokepoints linking colonies and trade routes
Racial order	Indigenous removal, chattel slavery until 1865, segregation and racialised territorial citizenship	Settler seizure, slavery until phased abolition after 1833, coercive labour and codified colonial hierarchy
Signature violence	Philippine–American War, Indigenous wars, Vietnam War, coups and counterinsurgency	Indian rebellions and reprisals, concentration camps in South Africa, colonial famines and counterinsurgency
Political vocabulary	“Expansion,” “security,” “free world,” “development” and “rules-based order”	“Civilisation,” “trusteeship,” “free trade,” “paramountcy” and the “white man’s burden”
Decolonisation	Retained Puerto Rico, Guam, American Samoa and other territories; shifted strongly toward informal predominance	Lost most major colonies between Indian independence in 1947 and the late 1960s, while retaining overseas territories
Enduring centre of power	Washington, the Pentagon, Wall Street and the dollar system	London, Westminster, the City, the Crown and Commonwealth networks

The chart does not compare unlike units with each other; it records two dimensions of British formal rule near their respective peaks.

The British Empire on its own terms

The British Empire evolved through conquest, settlement, slavery, company government and naval power rather than one constitutional design. The East India Company combined trade with taxation and war; after the Indian Rebellion of 1857, Parliament transferred its Indian administration to the Crown under the Government of India Act 1858. Settler colonies seized Indigenous land in Ireland, North America, Australasia and southern Africa, while Caribbean plantation colonies generated wealth through enslaved African labour.

Abolition did not erase extraction. The Slavery Abolition Act 1833 allocated £20 million in compensation to slave owners—about 40% of British government expenditure in 1833, according to University College London’s Legacies of British Slavery project—while formerly enslaved people received no compensation and many endured “apprenticeship” until 1838.

British rule also intensified vulnerability to famine. In India, the 1876–1878 famine killed an estimated 5.5 million people in British-administered provinces according to the official Famine Commission of 1880; historian Mike Davis later placed the wider regional toll at 6.1–10.3 million. Policy choices concerning grain exports, taxation and relief were integral, not incidental, to imperial governance.

“The sun never sets on the British Empire.” The phrase circulated widely by the 1820s; its popularity expressed the geographic reach of British possessions rather than equality among their inhabitants.

The American Empire on its own terms

The American Empire began with continental conquest. The Indian Removal Act of 1830 enabled expulsions including the Cherokee Trail of Tears; the US National Park Service estimates that about 4,000 of roughly 16,000 displaced Cherokee died during removal in 1838–1839. War against Mexico ended with the Treaty of Guadalupe Hidalgo in 1848, transferring about 1.36 million km²—approximately 525,000 square miles—to the United States.

The year 1898 made overseas empire unmistakable. The United States annexed Hawaiʻi and, after war with Spain, took Puerto Rico, Guam and the Philippines. The Philippine–American War began in 1899. A US colonial census published in 1905 estimated that 200,000 Filipinos had died from war, famine and disease; later scholarly estimates commonly range from 200,000 to 250,000 civilian deaths, while some estimates are higher.

“The Philippines are ours forever, ‘territory belonging to the United States,’ as the Constitution calls them.” — Albert J. Beveridge, 1900, In Support of an American Empire

After 1945, Washington usually preferred access and compliance over annexation. It combined military alliances, covert action, aid, sanctions, corporate investment and dollar power. The CIA helped overthrow Iran’s prime minister Mohammad Mosaddegh in 1953 and supported the operation that removed Guatemala’s president Jacobo Árbenz in 1954. Neither episode created a conventional colony; both restricted national sovereignty to protect strategic and economic interests.

Shared logic and real differences

Both systems secured land, labour, markets, raw materials and strategic routes while presenting domination as universal improvement. Each used racial classification to distinguish rulers from ruled; each mixed public force with private capital; each cultivated local intermediaries; and each punished governments or communities that obstructed extraction.

The strongest similarity is functional: sovereignty became conditional. London imposed treaties, officials and commercial rules through colonial offices, companies and gunboats. Washington more often works through military agreements, financial institutions, sanctions, intelligence services, multinational firms and allied elites. Formal annexation is therefore an incomplete test of imperial power.

The differences remain substantial. Britain’s empire at its territorial maximum was a legally differentiated system of colonies and dependencies governed from London. US hegemony after 1945 operated in an international order of formally sovereign states and faced the United Nations Charter’s prohibition on aggressive war. Britain depended on imperial preference and sterling networks; the United States sponsored the Bretton Woods institutions in 1944 and gained exceptional leverage from the dollar’s reserve role. British imperial administration placed large civilian bureaucracies abroad; American power more often separated military access, diplomatic pressure and market control from day-to-day government.

These differences affect responsibility, but they do not make one system non-imperial. Direct colonial government and informal empire are distinct mechanisms for producing unequal freedom.

Why the comparison is made—and resisted

The comparison is made because British power supplied precedents that US strategists studied: command of sea lanes, overseas bases, financial centrality and claims to uphold an open commercial order. The transfer was neither complete nor peaceful. Britain’s relative decline across the two world wars coincided with American financial and military ascent, while the 1956 Suez Crisis exposed London’s dependence when President Dwight D. Eisenhower pressured Britain, France and Israel to withdraw from Egypt.

It is resisted for political reasons. “Empire” conflicts with the US national story of anti-colonial independence, while British nostalgia isolates railways, law or language from conquest and coerced extraction. Another objection—that empire requires formal colonies—defines away protectorates, occupations, client governments and territorial exceptions. Conversely, treating every unequal alliance as imperialism empties the term of precision.

A useful comparison asks who could make binding decisions, whose property and mobility were protected, where profits flowed, and what happened when subjected people refused.

The comparison should not collapse different histories. The British destruction of autonomous states, US settler colonialism, Atlantic slavery, Indian famine, the Philippine war and postwar regime change require separate evidence. Comparison identifies recurring machinery; it does not create a single interchangeable victim count.

Sources & further reading

Frequently asked questions

Was the United States an empire like the British Empire?: Yes, but not in an identical form. Britain governed a formal empire that covered about 35.5 million km² in 1920. The United States annexed Indigenous lands and overseas territories, especially in 1898, then relied more heavily after 1945 on military bases, alliances, covert intervention, finance and sanctions. Puerto Rico, Guam and American Samoa remain US territories in 2026.
When did the American Empire begin?: There is no single agreed date. Continental settler conquest began in the colonial era and continued after US independence in 1776. Key markers include the Louisiana Purchase in 1803, the Indian Removal Act in 1830, the Mexican Cession of about 1.36 million km² in 1848, and the acquisition of Puerto Rico, Guam and the Philippines in 1898.
How large was the British Empire at its peak?: Historical territorial compilations place the British Empire at about 35.5 million km² in 1920, roughly 24% of Earth’s land. Its recorded population reached about 458 million in 1921. These peaks occurred in different years and should not be merged into one statistic, but together they indicate the scale of formal British rule after the First World War.
How did British and American imperialism differ economically?: Britain used chartered companies, colonial taxation, plantation slavery, imperial preference and sterling finance. The United States used territorial acquisition too, but after 1944 increasingly projected power through dollar finance, corporations, aid, sanctions and the Bretton Woods institutions. Britain more often embedded extraction in colonial administration; Washington more often influenced formally sovereign states through access, dependency and policy pressure.
Why do some historians call US foreign power an empire?: Historians use the term because the United States acquired overseas territories in 1898, suppressed Philippine independence from 1899, maintained unequal territorial citizenship and later shaped governments through military, economic and covert means. The CIA-backed operations against Mohammad Mosaddegh in Iran in 1953 and Jacobo Árbenz in Guatemala in 1954 are frequently cited examples of imperial power without formal annexation.

Related chapters

Comparisons

All hubs

Sources & further reading

CC BY 4.0 · 2026-08-04

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