The British Royal Navy—not the US military—enforced the Monroe Doctrine for most of the 19th century

The Monroe Doctrine was designed to keep Europe out of the Americas

First articulated in 1823 by President James Monroe, the doctrine declared the Western Hemisphere off limits to European colonization. It has since been invoked to justify US military interventions in Latin America, from Teddy Roosevelt's takeover of Venezuela to George H.W. Bush's arrest of Panama's leader Manuel Noriega.

A wave of Latin American independence movements most likely prompted the Monroe Doctrine

Between 1810 and 1822, many Latin American colonies separated from Spanish rule, 10 in the last two years. Concerns that Spain and its European allies might try to regain these republics were a main reason behind Monroe's declaration.

The Monroe Doctrine helped lead to the American occupation of territory abroad

This podcast explores how the policy motivated a century of US military intervention throughout Latin America, the Caribbean, and the Pacific—covering the annexation of Hawaii, the Spanish-American War, and occupations of Cuba, Haiti, and Panama.

Hear about why Europe obeyed the Monroe Doctrine, despite American military weakness

This podcast explores the European background of the Monroe Doctrine, highlighting France's efforts to install aristocratic Bourbon monarchs in the newly independent Latin American republics—and how US opposition, British threats, and Spanish resistance ultimately disrupted those plans.

Learn about the history of the Monroe Doctrine

CBS Sunday Morning explores the origins of the Monroe Doctrine, tracing how a 19th-century warning against European intervention shaped US foreign policy and influenced America’s role in the Western Hemisphere for generations.

The Roosevelt Corollary transformed the Monroe Doctrine from a defensive warning into a rationale for US military intervention

In 1904, President Theodore Roosevelt declared that the US had the right to exercise international police power in Latin America. Over the following two decades, the US intervened militarily in the region about a dozen times—often enough that Marines became known locally as "State Department troops."

The intellectual architect of the Monroe Doctrine was Secretary of State John Quincy Adams, not Monroe

Adams, the main foreign relations authority in the Cabinet, shaped the key parts of the Monroe Doctrine speech. He advocated for a unilateral American declaration to warn European powers, rejecting a potential joint statement with Britain favored by some Cabinet members.

France, Spain, and Britain formed a joint military alliance to force Mexico to repay its debts

In October 1861, the three powers signed the Convention of London and landed troops at Veracruz that December. Britain and Spain reached settlements with Mexico and withdrew. France refused and aimed to change the regime in power in Mexico.

Before Pearl Harbor, the US was a nonbelligerent ally to the Allied powers

Between September 1940 and December 7, 1941, the United States remained officially neutral—yet President Roosevelt incrementally shifted policy from “cash‑and‑carry” to Lend‑Lease, funneling critical military aid to Britain and other allies without entering the war.

The Barbary Wars were an early test of whether a president could wage war without a formal declaration from Congress

Jefferson sent naval forces against North African pirates without a congressional declaration of war, acting under his own authority. Years later, Madison took the opposite approach and formally sought congressional authorization.

Jefferson feared European control in the West of North America

Jefferson pushed for the Louisiana Purchase to prevent France or Spain from dominating the western frontier, securing control of the Mississippi River and vast lands that he felt were essential to America’s strategic and economic future.

British colonialism left economic institutions that still shape growth today

This analysis argues that while the British Empire inflicted exploitation and long-term harm, it also exported institutions—like standardized property rights and land surveying—that boosted economic development in some colonies.

Pontiac's Rebellion prompted Britain to draw a line between colonists and Native lands in 1763

After the French and Indian War, a coalition of Indigenous nations—led by Odawa leader Pontiac—launched a major uprising against British forts. In response, Britain issued the Royal Proclamation of 1763, which reserved lands west of the Appalachian Mountains for Native peoples.

The history of deep-sea mining and its governance by the International Seabed Authority

The British HMS Challenger research vessel identified metal-rich seafloor rocks between Hawaii and Mexico in the 1870s, but rules governing which nations control which parts of the ocean were not established until 1958 by the UN. It later established the ISA to oversee mineral-related operations in international waters.

Colonial Americans used tobacco, wampum, and land-backed notes to solve a chronic coin shortage

British coins rarely circulated in the colonies due to an unfavorable trade balance, forcing colonists to improvise. They traded in Spanish dollars, Native American shells, tobacco warehouse receipts, and eventually paper money backed by land rather than gold.

The US government ran boarding schools designed to erase Native American identity

From the late 19th century into the 20th century, the federal government sent Native children to boarding schools under the philosophy of "kill the Indian, save the man." Children were forbidden from speaking their languages or practicing their cultures, and many endured abuse.

The trans-Atlantic slave trade brought over 10 million enslaved people to the Americas

During the Atlantic slave trade (1526-1867), about 12.5 million Africans were forced onto ships; only 10.7 million survived to reach the Americas. Fewer than 400,000 arrived in what became the United States—the rest were taken to the Caribbean or Latin America.

A trading company became Britain's most powerful imperial force

The East India Company began as a private merchant venture and grew into Britain’s dominant power in India—amassing wealth, fielding armies, and governing tens of millions until the Crown took direct control in 1858.

Religion dominated many aspects of Colonial life and was enforced by the government

Eight of the 13 British Colonies in America had official, established churches, and laws mandated that everyone attend a house of worship and pay taxes that funded ministers' salaries.

The United States has had a tumultuous relationship with Cuba since its 1959 revolution, highlighted by a nuclear crisis and a decades-long trade embargo.

The US finished what the French had started with Panama's canal

For about two decades, Suez Canal-builder and Frenchman Ferdinand de Lesseps led the project, but financial troubles forced it into the hands of the US, who completed it in 1914. This timeline, made to accompany the definitive PBS American Experience documentary about the canal, highlights major moments in its construction.

250 years of world trade history

Adam Smith’s revolutionary ideas about free trade were often ignored throughout American history to protect domestic industry—until World War II caused a shift in sentiment about global trade.

Railroads and long-distance communication led to the development of time zones

Noon had been determined independently at each location based on when the sun was highest in the sky, but this became impractical for standardizing transportation. British star-mapping and navigation advancements established Greenwich as the prime meridian through Greenwich Mean Time, or GMT.

The Bill of Rights spent more than a century largely ignored by the courts

When ratified in 1791, the Bill of Rights applied only to the federal government, which exercised little direct control over daily life. It played a limited role in early constitutional law until the 20th century, when legal advocates began using it to challenge state and local laws.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

Many countries remained neutral after Russia's invasion of Ukraine

Following Russia's 2022 invasion of Ukraine, few nations outside the West imposed sanctions on Moscow. Major powers such as China, India, Brazil, and Turkey remained neutral, underscoring global divisions over how to confront Russian aggression.

Twain's ‘To the Person Sitting in the Darkness’ satirized American imperialism

The 1901 essay was a response to the Philippine-American War as well as Rudyard Kipling’s poem, “The White Man’s Burden,” which argued that Western nations had a moral duty to rescue non-Western nations from ignorance. Twain’s essay ironically encouraged lecturing citizens of the countries being invaded: “for the sake of the Business we must persuade him to look at the Philippine matter in another and healthier way. We must arrange his opinions for him.”

The rivalry between Alexander Hamilton and Thomas Jefferson centered on federalism—the question of how much power the federal government should hold relative to the states.

The US dollar is the most widely circulated currency in the world, and is involved in nearly 90% of global transactions

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement

After the Boston Tea Party, colonists switched to coffee, which became the main morning drink for revolutionaries.

Watch how deep-sea mining equipment collects and processes polymetallic nodules—metal-rich, potato-shaped rocks—from the ocean floor and creates environmentally damaging plumes of sediments.

The American cockroach is actually from Africa, an apparent hitchhiker aboard ships carrying enslaved people, with evidence suggesting the bug may have arrived in the New World as early as the 1600s.

Quincy Jones' 'Big Band Bossa Nova' helped introduce bossa nova—a jazz-influenced Brazilian genre—to the US

While El Niño moves warm Pacific Ocean waters east along the equator, La Niña moves them west, shifting where rainfall will become more common for months.

The Beatles' US label rejected the band's first two singles, 'Please Please Me' and 'From Me to You,' with one executive calling the band 'dead in the water.'

Abraham Lincoln was almost assassinated weeks before his inauguration as he traveled from Illinois to DC through Baltimore in 1861; it took two independent claims for Lincoln to be convinced the threat was real

The story of Dollree Mapp, whose legal challenge over her 1957 conviction for possessing "obscene material" led to a major strengthening of the Fourth Amendment

The concept of phantom limbs, the perception that amputated limbs are still present, dates back to a French military surgeon in the 16th century.

Explore fun facts from the USPS, including unique post office buildings, a stamp that traveled past Pluto, and more.

Poison ivy was sent to Europe in the 1600s as an exotic, ornamental oddity, where it was purposefully grown in the English royal gardens at Kew, the Faculty of Medicine in Paris, and a few other locations.

For centuries, it was common to sleep in two shifts: a few hours at the beginning of the night, and a longer period beginning around midnight

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

Long before Major League Baseball began allowing instant replay for balls and strikes, an umpire reluctantly used the technology to determine whether a hit was a home run, a move that inadvertently ushered in a new era for the sport.

The Mona Lisa's celebrity status and repeated restorations have obscured what made the painting so revolutionary for its time

In 2018, 26-year-old missionary John Allen Chau was killed by tribesmen after attempting to reach and evangelize on India's isolated North Sentinel Island

Famed poet TS Eliot rejected the manuscript for George Orwell's political fable 'Animal Farm,' writing that its criticism of authoritarianism was not 'the right point of view.'

In 2025, four executives from large tech companies were given positions in the US Army Reserves—including Palantir Chief Technology Officer Shyam Sankar, which reinforced Palantir's ties with the US military and its role as a leading defense partner.

Learn how monoclonal antibodies, which mimic the body's antibodies, can fight diseases like Ebola.