The US won every major battle of the Mexican-American War

US military professionalism gave America a decisive edge in the war

The professionalism and engineering expertise of West Point–trained officers—like Grant, Lee, and Meade—gave the US a major advantage in the Mexican-American War, helping them win every major battle.

Mexico’s political chaos weakened its defense against US invasion

Mexico’s post-independence instability—marked by coups, power struggles, and weak central control—left its northern frontier vulnerable. That political fragmentation shaped Mexico’s unpreparedness during the Mexican-American War and helped enable US conquest.

US troops committed widespread atrocities during the Mexican-American War

American volunteer regiments frequently looted towns, raped civilians, and executed prisoners—especially in occupied northern Mexico. Historians have documented how racial hatred and impunity fueled war crimes that were rarely punished by military leadership.

The Mexican-American War trained future Civil War generals

Many key military leaders of the Civil War—including Ulysses S. Grant, Robert E. Lee, and Thomas “Stonewall” Jackson—first saw combat in the Mexican-American War, gaining battlefield experience that shaped their later commands.

American annexation of Texas eventually sparked war with Mexico

After Texas won independence from Mexico in 1836, the US annexed it in 1845—despite Mexico’s refusal to recognize Texas as separate. That annexation, combined with a heated border dispute, triggered the Mexican-American War the following year.

How the US took half of Mexico

In just two years, the United States redrew the map of North America. Sparked by border disputes in Texas and fueled by President James Polk’s drive for expansion, the Mexican–American War (1846–1848) reshaped both nations.

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.

Zachary Taylor became a national hero during the Mexican-American War

General Zachary Taylor led US forces to key victories in northern Mexico, earning widespread fame for his leadership. His popularity from the war propelled him to the presidency in 1848.

Irish immigrants deserted the US Army to fight for Mexico

During the Mexican-American War, hundreds of Irish Catholic immigrants—facing discrimination in the US Army—defected to Mexico and formed the Saint Patrick’s Battalion. Though many were captured and executed, they remain honored as heroes in Mexico.

Mexico admired Lincoln for opposing the war and supporting Mexican sovereignty

As a congressman, Abraham Lincoln condemned the Mexican-American War as unjust. Years later, as president, he backed Mexico’s fight against French occupation. His principled stance earned enduring respect and monuments across Mexico.

Some historians claim that Mexico's victory at Puebla may have prevented France from arming the Confederacy

According to some experts, Napoleon III planned to ship weapons from Mexico to Confederate forces to break the Union naval blockade. The delay caused by the Battle of Puebla meant French resources didn't reach the Texas border until after the Union Army's decisive victory at Vicksburg.

Cinco de Mayo celebrates the Mexican victory at the Battle of Puebla

On May 5, 1862, Mexican forces under General Ignacio Zaragoza repelled a larger, more well-equipped French army at Puebla. The French endured roughly 500 deaths before retreating. Though the French ultimately captured Puebla a year later, the improbable one-day victory became a symbol of national pride.

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.

The Aztec Empire explained

Tenochtitlán grew into a powerful city-state supported by innovations such as chinampa farming and its central role in the Triple Alliance. Spanish forces later exploited internal rifts to overthrow the empire, but the city’s legacy endures in modern Mexico City’s historic core.

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.

Yellow fever sidelined more US troops than enemy fire during the Spanish-American War

The disease, transmitted by the Aedes aegypti mosquito, sickened more than 2,000 soldiers. Fewer than 400 American soldiers died in the 1898 war.

New research challenges the myth that Montezuma peacefully surrendered to Spain

For centuries, historians claimed Montezuma II willingly ceded control to the conquistadors, and that later Aztec resistance was a rogue uprising. Evidence now shows no peaceful handover occurred, revealing a far more turbulent and contested encounter between the two warring empires.

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

Who won the Vietnam War?

Who won the Vietnam War? The question of who won the Vietnam War has been a subject of debate, and the answer depends on the definition of victory. This Encyclopædia Britannica article explains why this question hasn't been definitively answered despite the two halves of Vietnam now existing under one flag.

The Union victory at Gettysburg marked a major turning point in the war

Fought July 1-3, 1863, the Battle of Gettysburg ended the Confederate invasion of the North. While the Union lost nearly 23,000 troops, its victory in one of America's most famous battles shifted the war's momentum decisively toward the North.

The Battle of Midway flipped the balance of power in Pacific naval dominance

Between June 4–7, 1942, U.S. carrier-based aircraft, aided by broken Japanese codes and radar detection, ambushed and sank all four Japanese fleet carriers while losing only one, decisively undermining Japan's offensive capacity and marking the turning point in the Pacific War.

Throughout most of the 1800s, US currency was backed by silver and gold

In post-Civil War America, the government moved to use only the gold standard. This was how US currency was backed for decades in the US. You can read a comprehensive explainer on the gold standard and its history in the US to learn more.

In June 2025, apprehensions of illegal border crossings at the US-Mexico border reached an all-time low

Total US-Mexico border encounters fell to just 25,228—the lowest monthly figure ever recorded by Customs and Border Patrol—with only 8,024 Border Patrol apprehensions and a single-day low of 136 detentions on June 28.

Five US presidents won the election despite losing the popular vote

Because presidents are elected through the Electoral College rather than a national vote, candidates can win while receiving fewer votes nationwide. John Quincy Adams, Rutherford B. Hayes, Benjamin Harrison, George W. Bush, and Donald Trump (2016) each won the presidency while losing the nationwide popular vote.

Texas beat USC in the 2006 Rose Bowl to win the national championship

In a matchup of undefeated powerhouses, Vince Young led Texas to a 41–38 victory over USC—capping what is widely regarded as the greatest college football game in history.

Why the US women's soccer team has been so dominant for three decades

The US women's soccer team has more Women's World Cups than any other team, and have ranked as the number one team in the world for over a decade. Perennial favorites, the organization is one of the most dominant in modern sports history. Author...

See a 3D reconstruction of Tenochtitlan, the Aztec capital that was home to an estimated population of 200,000 to 400,000.

The power and influence of the American presidency have expanded significantly over time—far beyond what the founders envisioned.

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.

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

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.

Brandi Chastain, the star of the 1999 US victory over China in the 1999 Women's World Cup, was a last-second choice to take the penalty kick that sealed the victory.

Hear about the 250-year history of the United States Postal Service, complete with some of its strangest deliveries, important innovations, and the figures that made it an American institution.

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

Experimental hantavirus vaccines and therapies, still under development, have long been funded by the US military.

The American Society of Civil Engineers' infrastructure report card gave the US a C in 2025, its highest grade since the project launched in 1998.

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

View the ten deadliest tornadoes in US history.

Watch contemporary footage covering the US-backed Shah of Iran fleeing the country in the face of the 1979 Iranian Revolution

Gerrymandering works through two techniques: cracking opposing voters across districts to dilute their power, and packing them into a few to waste their votes in lopsided majorities.

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

A 2019 Facebook event called on attendees to "Storm Area 51, They Can't Stop All of Us," resulting in countless memes, the creation of a music festival, and eventually the arrests of those who did try to approach the area.

Tattoos remain visible on your skin thanks to immune cells called macrophages

In 1984, Operation Smash Hit intentionally crashed a 239-ton train into a nuclear waste canister at 100 miles per hour to prove the canister's safety, which remained completely intact and lost just 0.29 of its 100 pounds of pressure.

See how fireworks are made and learn how metals like magnesium and copper are responsible for different colors.

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

In 1939, baseball star Lou Gehrig delivered his inspirational 'Luckiest Man' speech after retiring due to the health condition that now bears his name.

Clever Hans was a 1900s horse that was believed to be able to solve math equations, tell time, and read and comprehend German, until a psychology student discovered how he got his answers.

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.