Congress has formally declared war 11 times across five conflicts, the last in 1942

Presidents have often used military force without formal declarations of war

Although the Constitution grants Congress the power to declare war, American presidents have repeatedly ordered military action without formal declarations. These precedents have expanded executive authority in national security beyond what the framers likely envisioned.

A formal declaration of war automatically triggers hundreds of statutes granting the president sweeping domestic authority

Beyond authorizing military force abroad, a formal declaration activates a wide range of domestic powers, including authority over enemy property, trade restrictions, and emergency economic authority. It also waives the 60-day time limits under the War Powers Resolution.

The first test of America's war powers came just a decade after the Constitution was ratified

During the undeclared Quasi-War with France in 1800, the Supreme Court ruled in Bas v. Tingy that Congress had authorized a valid "imperfect war" through statutes alone, without a formal declaration, establishing that there is a legal spectrum between peace and declared war.

The US never formally declared war in Vietnam

Instead of formally declaring war, Congress passed the Gulf of Tonkin Resolution in 1964, granting President Johnson broad authority to use military force. The resolution became the legal basis for escalating US involvement without an official declaration of war.

Madison was America's first president during a formally declared war

During James Madison's presidency, Congress formally declared war on Britain in 1812 over its practice of seizing American sailors, trade restrictions, and repeated violations of US sovereignty—marking the first time a sitting American president led the nation through a declared war.

In the 1930s, Congress nearly passed a constitutional amendment requiring a national vote before declaring war

The Ludlow Amendment, proposed amid rising isolationism after World War I, would have required a national referendum before Congress could declare war, except in cases of direct attack. It was defeated 209 to 188 in 1938 after Roosevelt lobbied against it.

Congress has unsuccessfully voted on war powers resolutions over Trump's military operations in Venezuela and Iran

After Trump ordered unilateral military operations in both Venezuela and Iran without congressional authorization, lawmakers from both parties introduced war powers resolutions to block further action. Each effort failed, with Republican majorities largely supporting the president.

Hitler declared war on the United States four days after Pearl Harbor

Despite having no treaty obligation to join Japan’s fight, Hitler declared war on the US on Dec. 11, 1941. The move pulled America into the European theater and is widely seen as one of Hitler’s most strategic blunders.

President Polk deliberately provoked war with Mexico

After Mexico refused to sell California and New Mexico, President James K. Polk ordered US troops into disputed territory between the Nueces River and the Rio Grande—knowing it would likely spark a conflict. When fighting broke out, he used it to justify declaring war.

How much did WWII cost?

Though it lasted fewer than four years, World War II was the most expensive war in United States history, according to this infographic. Read through it to see how much WWII cost and learn about the consequences of financing such an expensive conflict.

The American War of Independence included over 1,500 military engagements

Several hundred of these were major battles like Yorktown, Saratoga, and Bunker’s Hill. This interactive map shows the locations of key locations of the conflict, highlighting major factors in each battle and their outcome.

The US Army inherited the Apache Wars after the Mexican-American War

The resolution of the Mexican-American War inserted the US Army into an ongoing conflict between Apache groups and outside powers—transforming local resistance into a decades-long struggle against American expansion known as the Apache Wars.

Was WWI really the first world war?

Was World War I the first true international conflict? This article thoroughly explores the meaning of the term world war. It also suggests a few previous conflicts, some of which involved battles in the Americas as well as Europe, that might have been more accurately described as a "world wars."

Bills passed during the Civil War shaped postwar America

Despite the war with the South, Congress passed transformative laws like the Homestead Act and the Morrill Land-Grant College Act, which encouraged westward settlement and expanded higher education.

Congress descended into fistfights, duels, and violence before the Civil War

In the decades before the Civil War, members of the United States Congress carried weapons, assaulted colleagues, and, in one case, a congressman killed another in a duel. The violence was driven largely by sectional conflict over slavery and foreshadowed the nation's descent into war.

The Civil War lasted for 4 years, with fighting taking place in a majority of the country

Fought from 1861 to 1865, the Civil War saw battles and raids across much of the country—from Pennsylvania to Texas and New Mexico to Florida.

11 states formed the Confederacy, with 2 others claiming allegiance

Between December 1860 and June 1861, 11 Southern states officially seceded to form the Confederacy. Pro-Confederate factions in Missouri and Kentucky also declared secession, but both states remained largely under Union control throughout the war.

NATO's Article 5 has been invoked once—after 9/11

The article was invoked the day after the attacks and launched a series of NATO campaigns to fight global terrorism. This page includes excerpts from a speech by then-NATO Secretary General Jens Stoltenberg about the attacks and the organization’s response.

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

The US and the USSR backed opposing sides in dozens of proxy wars during the Cold War

To avoid direct confrontation, the superpowers supported rival factions in conflicts around the world—including in Korea, Vietnam, Angola, and Afghanistan.

A history of every US government shutdown

There have been 21 shutdowns of the federal government in US history, a result of Congress's failure to pass appropriations bills in time. While the cause of most of the shutdowns stems from issues around the national debt and budget, a few originated in fights over unrelated policies. Dive into the history of each one with this comprehensive list.

The history of the Chinese civil war from 1945-49

Today's tensions were formed after the Chinese Communist Party defeated the Kuomintang shortly after World War II. Here's a thorough explainer on what happened.

Death taxes have helped fund wars since the 1860s

Death taxes date back to 700 BCE and were used in Ancient Rome and Ancient Egypt. In the US, they've been used to finance wars since the Civil War, and have been levied on both the estate and beneficiary. The estate tax created during WWI to help finance war efforts is still in effect today.

William Clark negotiated one-tenth of all ratified treaties between Native Americans and the US

After the expedition, Clark held key territorial and federal roles, overseeing western expansion and Native relations. While he expressed sympathy for displaced natives, he oversaw the transfer of millions of acres from Native nations to US control through various treaties.

The world rapidly decolonized after World War II

After WWII, weakened European powers faced mounting resistance from colonized peoples. Between 1945 and 1980, dozens of nations across Africa, Asia, and the Middle East gained independence.

The American Battle Monuments Commission maintains 26 overseas military cemeteries in 16 countries

The cemeteries honor more than 218,000 American war dead, with the majority of sites located in France and Belgium, where some of the heaviest fighting of both World Wars took place.

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 Russia-Ukraine conflict is the largest ground war in Europe since World War II in terms of casualties, forces mobilized, and displacement of civilians.

The United States is one of only around two dozen countries with a fully federal system of government, in which power is divided between national and state governments.

Despite being favored by 87% of Americans, Congress does not have term limits.

The original copy of the Declaration of Independence is not a pristine document, and even features a smudged anonymous handprint in the bottom left corner.

See the most iconic photos from four decades of LIFE magazine

11 people died from firework injuries in the US in 2024.

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.

One disco producer saw 'Star Wars' four times on its opening weekend and was so inspired that he recorded the album 'Star Wars and Other Intergalactic Funk,' which produced a chart-topping single.

Jimmy Carter signed a 1978 bill that legalized home brewing, a move credited with kick-starting the craft beer industry.

The US first hosted the World Cup in 1994, a tournament that lives in soccer infamy for its poor planning and the murder of Colombian player Andres Escobar, who'd accidentally scored on his own net.

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

Dozens of S&P 500 stocks, including Coca-Cola and Walmart—known as the dividend aristocrats—have increased dividends every year for 25 years

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

While the first exchange-traded fund (a 'basket' of different assets that can be bought and sold on a stock exchange) in the US only launched in 1993, the global ETF market has grown to more than $10T in the short time since.

Mark Twain spent decades feuding with the US Postal Service, convinced its costs and regulations were bureaucratic overreach.

'Shogun,' a 1980s TV series, helped popularize sushi in the US by stimulating an American interest in Japanese culture.

In 1915, workers recovered a submarine-like vessel from the Chicago River, prompting fears of German espionage

Before humans, the Soviet Union and the United States sent animals—including apes, dogs, and cats—to space during the Space Race.

Calculate how much of your tax dollars go to each federal program based on your income, filing status, and number of children

Sunflowers have long been a symbol of nuclear disarmament because they can extract large amounts of radioactive cesium from soil.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

The most expensive ad of all time was for Chanel No. 5 perfume and cost roughly $33M to produce in 2004—about $57M in today's dollars.