United States

Human beings reached the Americas during the last Ice Age, most likely by way of Beringia, the land and coastal corridor that joined eastern Siberia to Alaska when sea levels were low. Archaeological and genetic evidence places the earliest secure occupations of the Americas at least 13,000 to 15,000 years ago, with some sites and DNA studies pointing to an even earlier presence. Over thousands of years these populations spread across two continents and developed an extraordinary diversity of cultures adapted to deserts, forests, plains, and coasts.

Within the bounds of the future United States, agriculture based on maize, beans, and squash transformed many societies. The Ancestral Puebloans of the Southwest built masonry towns and cliff dwellings; the Mississippian peoples raised great earthen mounds and, at Cahokia near present-day St. Louis, sustained a city that around 1100 CE rivalled contemporary European centres in population. In the Eastern Woodlands, confederacies such as the Haudenosaunee (Iroquois) governed through sophisticated political compacts.

These were not static or empty lands but densely woven human worlds, with trade networks, oral histories, and systems of law and diplomacy. The arrival of Europeans after 1492 would bring catastrophic epidemics and dispossession, but the continent's Indigenous nations long predated, and would long survive, that encounter.

Turning points

1. c. 13,000 BCEPeoples & Migration

   Peopling of the Americas

   Humans were established across the Americas by at least 13,000–15,000 years ago, having entered via the Beringian land bridge and Pacific coast from Asia during the last Ice Age.

   ↗See the data

   [12]

2. c. 1100 CECulture & Ideas

   Cahokia at its height

   The Mississippian city of Cahokia, near present-day St. Louis, reached its peak as one of the largest urban centres north of Mexico, anchored by monumental earthen mounds.

   [12]

3. 1492 CEColonisation

   Columbus reaches the Caribbean

   Christopher Columbus's landfall opened sustained contact between Europe and the Americas, beginning an era of conquest, colonisation, and devastating disease for Indigenous peoples.

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   [5]

After tentative beginnings, England secured its first permanent foothold at Jamestown, Virginia, in 1607, a private venture financed by the Virginia Company of London. The colony survived disease, hunger, and conflict with the Powhatan peoples partly by turning to tobacco cultivation, which created an insatiable demand for labour. In 1620 a separate group of religious dissenters, the Pilgrims, founded Plymouth in New England, the first lasting colony in that region.

The future United States took shape as a chain of thirteen British colonies, each with its own character: Puritan New England, the commercial and ethnically mixed middle colonies, and the plantation societies of the South. From 1619, when an English ship landed 'twenty and odd' captive Africans at Point Comfort in Virginia, the colonies were drawn into the transatlantic slave trade. Over the colonial era slavery hardened into a hereditary, racialised system of chattel bondage, especially in the South, that would shape American life for centuries.

Colonisation came at the expense of Indigenous nations, who lost land through warfare, treaty, and the demographic collapse caused by introduced diseases. By the mid-eighteenth century the British colonies were populous, prosperous, and accustomed to a large measure of self-government through their own assemblies—an autonomy that imperial authorities in London would soon try to curb.

Turning points

1. 1607Colonisation

   Founding of Jamestown

   English settlers established Jamestown in Virginia, the first permanent English settlement in North America, financed by the Virginia Company of London.

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   [5]

2. August 1619Peoples & Migration

   First Africans landed in Virginia

   An English ship brought roughly twenty enslaved Africans to Point Comfort, Virginia, marking the beginning of African slavery in the English mainland colonies.

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   [11]

3. 1620Religion

   Pilgrims found Plymouth

   Separatist Pilgrims aboard the Mayflower established Plymouth Colony, the first enduring European settlement in New England.

   [6] [7]

4. 1754–1763War & Rupture

   French and Indian War

   Britain's victory in the North American theatre of the Seven Years' War expelled France from the continent but left Britain heavily indebted, prompting new colonial taxes.

   ↗See the data

   [12]

Figures of the era

After 1763, parliamentary taxes imposed without colonial consent—the Stamp Act, the Townshend duties, and others—ignited protest under the slogan 'no taxation without representation.' Confrontation escalated to bloodshed at Lexington and Concord in April 1775. On 4 July 1776 the Second Continental Congress adopted the Declaration of Independence, drafted chiefly by Thomas Jefferson, which proclaimed that 'all men are created equal' and possessed unalienable rights—an ideal starkly at odds with the slavery the new nation tolerated.

The War of Independence, won with crucial French assistance, ended with British recognition of American sovereignty in the Treaty of Paris (1783). The first national framework, the Articles of Confederation, proved too weak, and in 1787 a convention in Philadelphia drafted the Constitution of the United States. After fierce debate it was ratified once New Hampshire became the ninth state to approve it on 21 June 1788; the new federal government convened on 4 March 1789, and George Washington was inaugurated as first president on 30 April 1789. A Bill of Rights, ratified in 1791, guaranteed fundamental liberties.

The young republic established national institutions, asserted federal authority, and pursued continental expansion. The Louisiana Purchase of 1803 doubled the nation's territory by acquiring vast French claims west of the Mississippi, and the Lewis and Clark expedition (1804–1806) explored the new lands—accelerating a westward drive that would intensify pressure on Indigenous nations. The War of 1812 against Britain confirmed American independence and fostered a sense of national identity.

Turning points

1. 4 July 1776Independence

   Declaration of Independence

   The Second Continental Congress adopted the Declaration of Independence, formally announcing the separation of the thirteen colonies from Great Britain.

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   [1]

2. 1783War & Rupture

   Treaty of Paris

   Great Britain recognised the independence of the United States, ending the Revolutionary War and ceding territory east of the Mississippi.

   ↗See the data

   [12]

3. 21 June 1788Formation

   Constitution ratified

   With New Hampshire's ratification the Constitution took effect; the federal government began operating on 4 March 1789 and Washington was inaugurated that April.

   [1]

4. 1803Politics & Power

   Louisiana Purchase

   The United States bought France's Louisiana territory for $15 million, roughly doubling the nation's size and opening the trans-Mississippi West.

   [9]

Figures of the era

In the decades after 1815 the United States surged westward, driven by a belief in 'Manifest Destiny.' Expansion meant the forced removal of Indigenous nations—most notoriously the Cherokee Trail of Tears of 1838—and, after the U.S.–Mexican War (1846–1848), the annexation of vast southwestern territories. Each new acquisition reopened the explosive question of whether slavery would expand with the nation.

Slavery had become the foundation of the Southern economy, producing cotton for global markets on the labour of millions of enslaved people. A succession of fragile compromises—the Missouri Compromise of 1820, the Compromise of 1850, the Kansas–Nebraska Act of 1854—failed to settle the issue, and a militant abolitionist movement and a free-soil political coalition rose against the institution. The election of Abraham Lincoln in 1860 prompted eleven Southern states to secede and form the Confederacy.

The Civil War (1861–1865) began when Confederate forces fired on Fort Sumter in April 1861 and became a total war that killed an estimated 750,000 or more soldiers. Lincoln's Emancipation Proclamation of 1 January 1863 declared enslaved people in the rebelling states free and turned the war into a struggle for abolition. The Union victory, sealed by Robert E. Lee's surrender at Appomattox in April 1865, preserved the nation and led to the Thirteenth Amendment, ratified on 6 December 1865, which abolished slavery throughout the United States.

Turning points

1. 1838Peoples & Migration

   Trail of Tears

   Under the Indian Removal Act, the United States forcibly marched the Cherokee and other southeastern nations west of the Mississippi; thousands died en route.

   ↗See the data

   [12]

2. 1861–1865War & Rupture

   American Civil War

   War between the Union and the secessionist Confederacy, ignited at Fort Sumter, became the deadliest conflict in U.S. history and decided the fate of slavery.

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   [8]

3. 1 January 1863Politics & Power

   Emancipation Proclamation

   President Lincoln declared enslaved people in the rebelling states 'forever free,' redefining the war's purpose and clearing the way for Black enlistment in the Union army.

   [3]

4. 6 December 1865Politics & Power

   Thirteenth Amendment abolishes slavery

   Ratified after the Union victory, the Thirteenth Amendment abolished slavery and involuntary servitude throughout the United States.

   [2]

Figures of the era

Reconstruction (1865–1877) attempted to rebuild the South and secure rights for freed people: the Fourteenth Amendment guaranteed citizenship and equal protection, and the Fifteenth barred denial of the vote on grounds of race. But the withdrawal of federal troops and a violent white backlash overturned these gains, ushering in decades of racial segregation under 'Jim Crow' laws and disenfranchisement that endured well into the twentieth century.

The later nineteenth century brought breakneck industrialisation. Railroads bound the continent together, steel and oil empires arose, and tens of millions of immigrants—from Ireland, Italy, eastern Europe, China, and beyond—poured into expanding cities. This 'Gilded Age' generated immense wealth alongside sharp inequality, labour conflict, and movements for reform. The completion of continental conquest was marked by the closing of the frontier and the final subjugation of the Plains nations.

In the twentieth century the United States stepped onto the world stage. It entered the First World War in 1917, helping to decide the conflict. The prosperity of the 1920s collapsed into the Great Depression after the 1929 stock market crash, prompting Franklin D. Roosevelt's New Deal, which dramatically enlarged the federal government's role in economic life. The Japanese attack on Pearl Harbor on 7 December 1941 brought the United States into the Second World War, which it helped win in 1945, emerging as the world's preeminent economic and military power and entering the nuclear age.

Turning points

1. 1868Politics & Power

   Fourteenth Amendment

   Ratified during Reconstruction, it granted citizenship to all persons born in the United States and guaranteed equal protection of the laws.

   [12]

2. 1869Economy & Trade

   Transcontinental railroad completed

   The joining of the rails at Promontory, Utah, linked the Atlantic and Pacific coasts, accelerating settlement, commerce, and industrial growth.

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   [12]

3. 1929Economy & Trade

   Great Depression

   The stock market crash of 1929 triggered a decade-long economic collapse, answered by Roosevelt's New Deal programmes of relief, recovery, and reform.

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   [12]

4. 7 December 1941War & Rupture

   Attack on Pearl Harbor

   Japan's surprise attack on the U.S. naval base in Hawaii brought the United States into the Second World War.

   ↗See the data

   [4]

Figures of the era

After 1945 the United States led the Western bloc in a Cold War rivalry with the Soviet Union that spanned proxy conflicts in Korea and Vietnam, a nuclear arms race, and the space race that culminated in the 1969 Moon landing. At home, postwar prosperity expanded a vast middle class, while suburbanisation and consumer culture transformed everyday life.

The most profound domestic struggle was the civil rights movement, which dismantled the legal architecture of segregation. The Supreme Court's Brown v. Board of Education (1954) ruled school segregation unconstitutional; mass nonviolent protest led by figures such as Martin Luther King Jr. pressed the cause; and Congress enacted the Civil Rights Act of 1964, barring discrimination in public life, and the Voting Rights Act of 1965, protecting the franchise. These laws transformed American democracy even as struggles over racial and economic justice continued.

The Cold War ended with the dissolution of the Soviet Union in 1991, leaving the United States the world's sole superpower. The decades since have been marked by globalisation, a digital and information revolution, the shock of the 11 September 2001 terrorist attacks and ensuing wars, and intense debate over immigration, inequality, and national identity. The United States remains a nation continually contesting the meaning of the ideals proclaimed at its founding.

Turning points

1. 1954Politics & Power

   Brown v. Board of Education

   The Supreme Court ruled that racial segregation in public schools was unconstitutional, a landmark in the legal assault on Jim Crow.

   [12]

2. 2 July 1964Politics & Power

   Civil Rights Act

   Signed by President Johnson, the Act outlawed discrimination based on race, colour, religion, sex, or national origin in employment and public accommodations.

   [10]

3. 6 August 1965Politics & Power

   Voting Rights Act

   The Act banned racial discrimination in voting and authorised federal oversight of elections, dramatically expanding Black political participation.

   [10]

4. 1969Culture & Ideas

   Apollo 11 Moon landing

   American astronauts became the first humans to walk on the Moon, a defining achievement of the Cold War space race.

   [12]

5. 1991Politics & Power

   End of the Cold War

   The dissolution of the Soviet Union left the United States as the world's sole superpower and reshaped the international order.

   [12]

Figures of the era