The first combat-deployed submarine vessel debuted during the American Revolution.

When German submarines lurked in US coastal waters

During World War II, German submarines (also known as U-boats) prowled the Southern coast of the US in 1942 and 1943, sinking more than 60 ships and killing 600 Allied soldiers. The campaign is less well-known, since the major battles in Stalingrad and Midway happened at the time. Several of these submarines and the ships they sank are now popular diving spots.

The Foolkiller: the mysterious submarine at the bottom of the Chicago River.

In November 1915, a submarine was found at the bottom of the Chicago River. It had been there for at least 10 years, was 40 feet long, and contained the remains of a man and his dog. To this day, no one knows who built it.

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

NYC's first subway was built largely in secret

In 1870, Alfred Ely Beach secretly tunneled under Broadway in 58 nights, disguising his pneumatic subway as a mail tube to fool Tammany Hall, the corrupt political machine that ran New York City. Nearly half a million New Yorkers rode it before politics, and a stock market crash killed the project.

Fracking originated in the American Civil War

After witnessing how artillery created fissures in narrow water channels, a Civil War veteran wondered if the process could be replicated in underground wells to extract oil. He patented an "exploding torpedo" for this purpose, which became the foundation for future fracking techniques.

A pet turtle survived a fatal barrel plunge over the falls

In 1930, George Stathakis died attempting a barrel stunt over the falls—but his 150-year-old pet turtle "Sonny" survived 24 hours trapped behind the cascade.

An archive of some of America's most significant shipwrecks

From The Portland—known as New England's "Titanic"—to the Civil War's USS Monitor, this archive from the National Oceanic and Atmospheric Administration provides overviews of some of the most well-known shipwrecks in US history.

Santa Barbara divers helped innovate deepwater diving technology

Divers in the Santa Barbara channel innovated a more efficient type of diving helmet in the 1960s that used helium to allow for longer, deeper excursions for oil surveying, abalone collecting, and more. These innovators have since set the standard worldwide for military and industrial diving.

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.

Humans have used bioluminescence as a means of military advantage

During World War I, the British Navy sank a German U-boat after spotting the blue light forming at the sides and in the wake of the boat. Jellyfish slime was applied to a Roman walking stick for nighttime guidance, while bioluminescent fungi in Indonesia fulfilled the same purpose.

Revolutionary War reenactments have taken place for centuries

The first known reenactment of the war occurred in 1778, while the war was still ongoing. A journal entry from a lieutenant colonel in the Continental Army remarked that soldiers had commemorated a “Glorious victory obtained over the British” at Saratoga with “a Grand sham fight.”

How slugs helped soldiers during WWI

Slimy, squishy, slow-moving, and heroic? Slugs are land-dwelling mollusks known mostly for causing havoc in our gardens. But during World War I, slugs saved numerous soldier's lives as poison gas detectors. Learn how the unpleasant creatures earned their stripes in the battle to protect soldiers from chlorine, phosgene, and mustard gas as organic detectors.

Boston opened the first subway tunnel in the US in 1897

By the end of the 19th century, nearly 400,000 people were packed into less than a square mile of downtown Boston, with 8,000 horses pulling trolleys through streets choked with noise, manure, and congestion. This prompted the city to pursue a then-controversial subway system.

Small wooden tail fins modified torpedoes to operate in the harbor's shallow water

Japan's existing Type 91 torpedoes weighed two tons and slammed into the water at 200 mph, diving 150 feet before rising again. Pearl Harbor was only 40 feet deep, requiring engineers to modify the existing torpedoes for the attack.

Why were tanks invented?

Tanks first appeared in warfare in World War I. As old methods of conducting battles proved ineffective, the idea of an armored vehicle that could traverse almost any terrain and carry a cannon came to fruition. World War I provided the impetus and finances to develop the modern tank. Learn more in this short but detailed article.

The oldest restaurants in the US

This list features several establishments that have been around since before the Declaration of Independence, including the White Horse Tavern, in Newport, Rhode Island, and New York's Fraunces Tavern, where George Washington dismissed his troops at the end of the Revolutionary War.

Recovering the USS Oklahoma was the largest naval salvage operation ever attempted

In 1943, engineers spent three months using 21 giant winches and an intricate cable system to right the capsized USS Oklahoma. It was the largest naval salvage effort ever attempted at the time and remains one of the most complex in history.

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.

Sailor tattoos represent naval milestones

Sailors often come home with mermaids or turtles adorning their bodies. But what does it mean to have permanent images of propellers on your bum, British galleons with soaring tiers of sails on your chest, or a bicep portrait of the Roman god Neptune? Those tattoos represent meaningful naval milestones.

Advanced forensic science has helped identify killed sailors decades later

When the USS Oklahoma capsized amid the attacks, hundreds of sailors were buried within the ship's hull. Officials have used advances in forensic science to analyze DNA and dental evidence to help identify nearly 400 sailors decades after the fact.

The 1915 sinking of the Lusitania precipitated World War I

In 1915, the British RMS Lusitania sank after being torpedoed by a German submarine. The Germans claimed the ocean liner was transporting munitions. Almost 1,200 civilians were killed in the disaster, which became a symbol of German aggression in the lead-up to World War I.

Watch how engineers salvaged almost every sunken ship at Pearl Harbor

This four-part video series explains the massive effort to raise, repair, and refloat the Pacific Fleet—detailing the engineering challenges, diving operations, and months of around-the-clock work that restored all but three damaged ships to active service.

In 1820, a sperm whale sank a ship from Nantucket, MA, events that would later inspire Herman Melville to write 'Moby-Dick.'

To survive underwater hibernation, some freshwater turtles perform cloacal breathing—blood vessels absorb dissolved oxygen from water drawn into the organism's cloaca, or rear orifice.

Where the world's most wanted pirate hid in the 1600s

Metal detectorists who discovered 500-year-old silver coins have helped support the theory that notorious 16th-century pirate Henry Every hid out in several American colonies.

Debunking myths about the American Revolution

The history of the American Revolution and the establishment of democracy are proudly taught in the US, but a number of incorrect details continue to be circulated. This article debunks some of the myths that persist in the public consciousness, like the idea that the war was solely driven by taxes or that Paul Revere was the only rider warning the rebels about the British.

Squanto was a tragic character in the original Thanksgiving story

Tisquantum (also known as Squanto) played a crucial role in the survival of the Pilgrims. As an English speaker, Squanto assisted the Pilgrims in gathering food and communicating with other Native peoples. However, his story also involved being sold into slavery by an English sea captain and returning home to find his tribe decimated by disease during the Great Dying. Tisquantum met his end not long after that first Thanksgiving, with historians speculating he died either by disease or assassination.

The USS Nevada was refloated within three months—and later fought at Normandy

Badly damaged at Pearl Harbor, the USS Nevada was raised by February 1942 after extensive salvage work. Repaired and modernized, it returned to action and bombarded German defenses during the D-Day landings.

A Navy messman with no gunnery training defended his ship at Pearl Harbor

Doris “Dorie” Miller, a Black Navy messman assigned to steward duties rather than a combat role, seized a .50-caliber machine gun aboard USS West Virginia during the attack. Despite no formal weapons training, he fired until out of ammo—becoming the first African American to earn the Navy Cross.

World War II's Battle of Savo Island was the worst wartime naval defeat in US history

On Aug. 9, 1942, a larger, radar-equipped Allied fleet lost four heavy cruisers off Guadalcanal in the Pacific theater without sinking a single Japanese ship. The Navy kept the humiliating rout secret from the public for years. Experts argued failure resulted from fractured command, not inferior arms or ships.

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.

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

After the Boston Tea Party (1773), colonists boycotted tea and turned to coffee, with coffeehouses becoming hubs for revolutionary discussions. The stimulating import from the Caribbean helped shape the nascent American taste.

Watch footage from the moments the Titanic wreck was discovered by a joint US-French research team in 1985.

The first Boston Marathon was held the next year

In 1897, the manager of the US Olympic team organized the first Boston Marathon, which featured a field of 15 runners. The race took place on Patriots Day, a holiday commemorating the first battles of the American Revolution.

Explore the life and presidency of George Washington, whose two terms in office were defined by precedent-setting, restraint, and institution-building.

As the first president, Washington established lasting norms: enforcing civilian control of the military rather than placing it in the hands of generals, forming a Cabinet, asserting federal authority during the Whiskey Rebellion, and voluntarily stepping down after two terms.

The Pearl Harbor attack was influenced by a British raid on Italian battleships

Japan closely studied Britain’s 1940 attack at Taranto, where carrier-launched torpedo planes crippled Italian battleships in shallow water. Although Japanese planning for Pearl Harbor was already underway, Taranto demonstrated the plan’s feasibility and strengthened Japanese confidence that a surprise carrier assault could cripple the US Pacific Fleet.

Emanuel Leutze's painting 'Washington Crossing the Delaware' is one of the defining images of the Revolutionary War.

The Mint’s first circulating coins were 11,178 copper cents

Congress authorized the first national mint in Philadelphia. The next year, the Mint delivered its first circulating coins, which were bigger than today’s quarters. This article shows more early US currency.