US military professionalism gave America a decisive edge in the war

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.

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.

Washington's military acumen and political judgment were crucial to the Continental Army's success

In this podcast, Pulitzer Prize-winning historian Rick Atkinson argues that Washington's endurance, strategic communication, political judgment, and ability to elevate capable subordinates proved decisive, in sharp contrast to the failures of British leadership during the war.

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.

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.

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.

The Panama Canal boosted the US as a world power in trade, engineering, and finance

The effort proved the US could achieve grand engineering projects while granting it influence over (and benefitting economically from) a major interoceanic channel and its host country, Panama.

Manifest destiny fueled US aggression against Mexico

The belief that the United States had a divine right to expand westward—known as manifest destiny—justified President Polk’s push for territorial conquest. It shaped public support for the Mexican-American War and framed the invasion as national destiny.

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.

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 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.

War-making authority is divided between Congress and the president in the Constitution

Article I grants Congress the power to declare war and fund the military, while Article II makes the president commander in chief. However, the Constitution does not clearly delineate where one authority ends and the other begins, creating a tension that has never been fully resolved.

Explaining the final battle of World War I

The Meuse-Argonne Offensive was the last battle of the First World War. Beginning in September and ending November 11, 1918, the battle was a tumultuous event and the first time the American Army fought on the world's stage. America simultaneously achieved victory and discovered new methods to fight a war. This Apple History podcast provides the details.

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.

World War I brought attention to US reliance on mineral imports

Domestic stockpiles were inadequate for the extended trade disruptions caused by the four-year war. In response, the US Geological Survey increased its geological mapping to help search for important metals alongside new oil fields for fuel.

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

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.

A book series aimed at World War II soldiers helped popularize works like 'The Great Gatsby' and 'Of Mice and Men.'

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.

Japan had the world's best carrier aviation in 1941

In late 1941, Japan possessed the world’s most powerful carrier fleet and the best-trained naval aviators, giving it a short-term edge over the US. But Japan couldn’t replace ships or pilots quickly, and US industry would soon outbuild it.

The National Guard serves both state governors and presidents

Roughly 430,000 trained military personnel act as a strategic reserve for the US military, deployed domestically during natural disasters or unrest as well as overseas. It consists of the Army National Guard and the Air National Guard, overseen at the federal level by the National Guard Bureau.

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.

The 1969 moon landing was a defining Cold War victory for the US

When Apollo 11 astronauts stepped onto the moon in July 1969, it marked a dramatic win in the US-Soviet space race. The televised landing—broadcast across the globe—showcased American technological supremacy.

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

The history of ARPANET and how it helped the US military during the Cold War

President Dwight D. Eisenhower established the Advanced Research Projects Agency in 1958, which recruited scientists to design the first large-scale computer network to support the American military during the Cold War. Academics would use the network to communicate via email among several US research universities.

A WWI war helmet outperformed modern gear in this study

Your great-grandparent's World War I helmet stuffed in the back of a closet may be just as effective at preventing brain injury from some blasts as a modern-day military helmet. This article further explains a study that pitted WWI and modern helmets against each other.

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.

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.

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

Iran's Revolutionary Guard Corps is independent of Iran's regular army and is one of the most powerful and influential military-political organizations in the Middle East.

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.

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.

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

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

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.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

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.

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

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

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.

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.

Warren Buffett's former professor Benjamin Graham is known as the 'father of value investing,' a strategy in which investors seek to buy stocks trading below their intrinsic worth.

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.

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

A small portion of The Winstons' 'Amen, Brother,' an obscure '60s gospel record, is the basis for thousands of hip-hop tracks, making it one of the most sampled records ever that's informally known as 'the Amen break.'

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

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.'