The Mexican-American War trained future Civil War generals

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.

See the army generals who helped define the Civil War

Hear profiles of the Union and Confederate commanders whose choices defined the war's outcome—from Grant and Lee to Sherman, Jackson, and others. See how their actions, tactics, and skills shaped the Civil War.

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

Despite being outnumbered in key engagements, US forces defeated Mexican armies across every major front. Superior training, leadership, and logistics allowed the US to win decisively—capturing Mexico City without losing a single major battle.

Ulysses S. Grant's leadership proved decisive in victory—and shaped postwar America

Elevated to general-in-chief in 1864, Ulysses S. Grant unified the Union strategy and forced a Confederate surrender at Appomattox. Elected president in 1868, he worked to enforce Reconstruction laws and protect the civil rights of freed African Americans.

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.

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.

Explore the social and cultural history of the Mexican-American War

Historian Peter Guardino joins host Don Wildman to explore how the war shaped ordinary lives on both sides of the border. Drawing from The Dead March, the episode reveals how culture, class, and ideology shaped the conflict and its consequences.

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.

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.

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.

Learn how Mexico’s anti-slavery stance shaped the US–Texas conflict

Historian Alice Baumgartner explores how Mexico’s abolition of slavery clashed with Anglo settlers' ambitions in Texas. The episode reveals how enslaved people fled south to freedom, reshaping the politics that led to Texas independence and the Mexican-American War.

The Civil War introduced many technological advances to both society and warfare

The conflict accelerated innovations—including railroads, telegraphs, ironclad ships, and mass-produced weapons—while advances in photography, medicine, and manufacturing transformed how Americans communicated, healed, and built after the war.

The Mexican-American War led to the birth of the Associated Press

To cover the distant war efficiently, rival New York newspapers pooled resources to share reports from the front—forming what became the Associated Press. The war marked a turning point in how Americans received real-time news about foreign conflicts.

Cinco de Mayo holiday celebrations originated with California's Mexican Americans during the Civil War

California Latinos first celebrated Cinco de Mayo in 1862 through patriotic assemblies called Juntas Patrióticas. Ardent Union supporters, these individuals saw the Puebla victory as a win for democracy against both French imperialism and the Confederate cause.

Future President Abraham Lincoln challenged Polk’s justification for war with Mexico

As a freshman congressman, Abraham Lincoln introduced the “Spot Resolutions,” demanding President Polk prove that Mexico had attacked on US soil. This constituted Lincoln’s first major political stand and highlighted growing dissent over the war.

Twain served in a Confederate militia for two weeks

In 1861, a 25-year-old Twain joined the Marion Rangers, a pro-Confederate militia. The group disbanded after two weeks upon hearing that Ulysses S. Grant, General of the Union Army, was headed their way. Twain moved to Nevada, where he eventually took a job at a newspaper.

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.

Guerilla warfare was a significant part of the success of the Americans

Francis Marion, also known as the Swamp Fox, was a Patriot general who used guerrilla warfare tactics in the Carolinas during the Revolutionary War’s southern campaigns. Also called “maneuver warfare,” the approach focuses on disorienting the enemy and exploiting their weaknesses while avoiding their strengths.

Hughes reported on Black Americans volunteering in the Spanish Civil War

In 1937, the Baltimore Afro-American newspaper sent him to cover the Black soldiers who’d left the US to fight in the International Brigades cooperating with the Republicans in the Spanish Civil War. Hughes’ dispatches mainly focused on the racially integrated military companies, something that was prohibited in the US.

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

The five declared wars were the War of 1812, the Mexican-American War, the Spanish-American War, World War I, and World War II. Every major American military conflict since Korea, Vietnam, Iraq, and Afghanistan has been fought without a formal declaration.

How Emily Dickinson and Walt Whitman grappled with the American Civil War

Whitman, whose brother was injured while fighting for the Union, was often overt in his pro-Union poems. Dickinson, whose brother paid to have someone enlist under his name, was more subtle, though equally as affected, as this comparative analysis makes clear.

See how the elite warriors of the Aztec Empire trained

This video explores the Aztec military’s elite Eagle and Jaguar warriors, known for their courage and combat skills, and highlights their rigorous training regimen. It concludes with a workout routine modeled on their methods.

At age 22, Washington inadvertently started the French and Indian War

In 1754, while leading a small Virginia militia force in the Ohio Valley, Washington's troops ambushed a French scouting party. The clash heightened tensions between Britain and France and sparked a broader conflict that soon spread across North America, Europe, and parts of Africa and Asia.

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

Catalonia and the War of the Spanish Succession

The War of Spanish Succession (1702-1715) was an international and civil war that reshaped Europe’s political landscape and brought Catalonia under Spanish rule. Created by the Museum of the History of Catalonia in Barcelona, this virtual exhibit guides readers through the 13-year war with a specific eye for its effects on Catalonia. Galleries of artwork from the period on the right-hand side of the page help immerse visitors in the history.

Clark’s maps provided the first detailed record of the American West

Covering over 8,000 miles, William Clark’s maps charted rivers, mountains, and tribal territories with remarkable accuracy. Equipped with sextants, compasses, telescopes, and more, Clark became an expert at surveying—requiring extensive celestial and topographical observations each day.

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

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

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.

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

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

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 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.

Many legends about George Washington, including his supposed wooden teeth and the story of cutting down the cherry tree, lack evidence.

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

Mid-century modern graphic designers, known for their bright colors and bold lines in advertising, also found success with children's books.

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.

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

See 33 images that became central to huge scandals, including a young Charles and Camilla, Michael Jackson's baby on a hotel balcony, and Hugh Grant's mugshot.

Salvador Dalí believed he was his own dead brother, who had died nine months before he was born

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

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

View the ten deadliest tornadoes in US history.

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.

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 term 'algorithm' originated from the Latinized name of al-Khwārizmī, a 9th-century mathematician whose works introduced Arabic numerals and the decimal-based numeral system to Europe and whose treatise 'Al-Jabr' gave algebra its name.

See how Budweiser's famous Clydesdales spend their days at Warm Springs Ranch, where roughly 70 to 80 of the beer brand's giant horses can be found at any given time.

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

Poison ivy's characteristic rash is caused by an allergic response to an oily compound in the plant called urushiol.

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.