1

The horse diaper

Image: Lucia Macedo

Designed to catch manure in crowded cities—a problem once so severe that it shaped public infrastructure as well as the entrances to houses—the horse diaper was an invention meant to be strapped beneath working horses pulling carts and carriages.

The idea was to reduce disease and street filth during the horse-powered urban era. While the device saw limited use before automobiles rapidly replaced horses, similar designs are still occasionally used in modern veterinary practice.

2

The baby cage

Image: Taylor Flowe

Built as wire cages attached to apartment windows, so-called "baby cages" allowed infants to get fresh air when outdoor space was unavailable. Some models were guaranteed to safely hold over 30 pounds.

While alarming today and ultimately abandoned due to obvious safety concerns, the designs likely inspired some of the baby-proofing nets used today.

3

The pneumatic subway

Image: Eddi Aguirre

In the late 1860s, American entrepreneur and inventor Alfred Ely Beach set out to prove the feasibility of a human-sized pneumatic subway system beneath New York City, capable of moving both people and cargo using nothing more than air pressure.

The prototype was set up as a public attraction and carried passengers along a tunnel just over 300 feet long, from a station to a dead end. Despite its initial success, bureaucratic obstacles and high costs halted expansion, leaving it as a functional but largely forgotten underground experiment.

4

The mechanical horse

Image: Gabriel Tovar

Created for exercise and riding practice, the mechanical horse used a system of gears, cranks, and pedals to simulate walking and trotting motions while the rider sat in a saddle-like seat. It was marketed to urban riders and cavalry trainees who lacked access to stables or live horses.

Though bulky and impractical for widespread use, the device anticipated modern fitness machines by replicating real-world movements for conditioning and skill retention, rather than simple repetitive exercise.

5

The first metal detector

Image: Fer Troulik

After a failed assassination attempt on President James Garfield, Alexander Graham Bell hastily built an early metal detector in an effort to locate the bullet lodged in his body. The device functioned as intended, but it was unable to find the bullet because metal bed springs interfered with the signal.

Despite this setback, Bell’s early design proved the concept and directly influenced the development of modern metal detectors.

6

The pet-powered butter churn

Image: Matt Bero

In an inventive twist on animal-powered machinery, some 19th-century American farmers rigged small treadwheels for dogs, cats, or even goats to generate kinetic energy for churning butter. The animal ran inside the wheel, turning a rope or pulley connected to the churn.

While technically functional, the system was limited by the animal's willingness to cooperate and the small amount of power it generated.

7

The umbrella hat

Image: Claudio Schwarz

Robert W. Patten, often called the "Umbrella Man," patented one of the first commercially successful hands-free umbrella hats. It strapped a small umbrella directly to the wearer’s head, providing both sun and rain protection while keeping the hands free for work or walking.

His original design even included a mosquito net attached to the canopy. Patten didn’t enjoy much commercial success but became somewhat of an eccentric and comical popular figure, partly due to a series of comics that were inspired by his unusual invention.

8

The one-wheel motorcycle

Image: CJ Toscano

In 1971, American inventor Kerry McLean built and refined a monowheel—a one‑wheeled motorized vehicle in which the rider and engine sit inside the wheel’s circumference.

Since then, various attempts have been made to build on his original design, but it remains a niche vehicle used primarily for entertainment rather than practicality, as riders must be highly skilled simply to turn or even stay upright.

9

The first talking doll

Image: Holly Ward

In 1890, Thomas Edison embedded miniature versions of one of his most popular inventions —the phonograph—inside dolls so they could recite nursery rhymes.

While the idea was innovative, the technology was not yet there. The recordings were fragile, distorted, and often failed to work properly. The dolls were pulled from the market within weeks due to customer complaints, making it one of Edison’s rare commercial failures.

10

The glass harmonica

Image: Francesco Bovolin

Faithful to his eccentricity and inventive spirit, Benjamin Franklin redesigned the existing glass harp into a rotating spindle of glass bowls, played by touching the spinning rims with wet fingers, which he called the "glass harmonica."

The instrument produced eerie, sustained tones unlike anything else of its era. However, its fragile nature made it somewhat impractical, and the rotating mechanism posed a potential danger to the player if anything went wrong.

1

There's an unexplained billion-year gap

Look closely at the canyon walls, and you'll notice something strange: a clean, sharp line where ancient rock simply stops, and a much younger layer begins directly above it.

This geological puzzle is called the "Great Unconformity," and it represents over a billion years of rock layers that are simply absent , as though that stretch of time never happened. In some spots, rock dated 1.8 billion years old sits directly beneath rock that is only 520 million years old. Where did the missing billion years go?

The leading theory involves the violent breakup of an ancient supercontinent, but scientists are still piecing it together.

2

During the Cold War, it hid a nuclear fallout shelter

During the Cuban Missile Crisis in 1962, the U.S. government converted part of the Grand Canyon Caverns into a fallout shelter. This dry cave system, more than 200 feet underground, was stocked with enough food and water to sustain 2,000 people. Naturally, it was never occupied, and the supplies were never used.

The caverns have since been transformed into a tourist attraction, with organized tours winding through the same underground chambers that were once intended as a refuge from nuclear war. You can even book a night's stay there.

3

The Federal Aviation Administration was founded after a crash over the canyon

In 1956, two commercial passenger planes collided in midair over the eastern Grand Canyon, killing all 128 people on board both crafts. Rescue teams struggled to reach the wreckage deep inside the canyon, and the extreme heat of the crash had caused the planes' aluminum to fuse with the bedrock. There were no survivors.

The disaster exposed a terrifying truth: the U.S. air traffic control system was dangerously outdated, relying on pilots' visual estimates and rough guesswork from controllers , with no way to separate fast-moving aircraft from slow ones, or instrument-flying planes from those navigating by sight. Congress responded by passing legislation that created both the Federal Aviation Administration (FAA) and the National Transportation Safety Board.

4

A hoax suggested that an Egyptian civilization had lived there

In 1909, the Arizona Gazette reported that an explorer named G. E. Kinkaid had discovered a vast underground citadel inside the canyon, filled with artifacts linked to ancient Egyptian civilization. He even claimed the expedition had been funded by the Smithsonian.

This story described hieroglyphics on the walls, mummies in the chambers, and relics pointing to a direct connection with the Egypt of the pharaohs. It was incredibly detailed, and it was, of course, a hoax. No evidence for any of Kinkaid's claims ever surfaced.

5

Fewer than 100 people have ever hiked its full length

Among the few people who have completed the through-hike of the Grand Canyon is Jen Hogan, the first woman to accomplish it, finishing her journey in 2021–2022.

It’s a full 800-mile length below the rim. The route involves extreme heat, flash floods, near-impassable areas, and stretches with no water or trail whatsoever. Around 60 or 70 people have reportedly accomplished it. This makes it one of the most exclusive feats on Earth.

6

The Grand Canyon's rocks predate dinosaurs entirely

Visitors scanning the canyon walls for fossils are often surprised to learn they won't find any dinosaur bones here. The rock layers of the Grand Canyon are simply older than dinosaurs. This fact alone can be shocking: staring at its walls means staring at marine fossils from as far back as 1.2 billion years ago. Some of its caves hold the remains of ancient mammals. The canyon is a window into a world that existed long before the dinosaurs, when the land that is now Arizona lay beneath a shallow sea.

7

The park is bigger than Rhode Island

Numbers alone rarely capture the Grand Canyon's scale, so here's a different approach. Rhode Island covers about 1,214 square miles, and the Grand Canyon National Park spans 1,904 square miles.

The canyon's depth exceeds four Empire State Buildings (which is 1,454 feet) stacked on top of one another. That’s 6,093 feet at its deepest point.

8

But it's not the deepest canyon on Earth

For all its grandeur, the Grand Canyon does not hold the depth record. Pictured above, the Yarlung Tsangpo Grand Canyon in Tibet, China, plunges to 17,567 feet, which is nearly three times deeper. Carved by the Yarlung Tsangpo River as it cuts through the eastern Himalayas, that canyon is so remote and extreme that it remained largely uncharted until the late 20th century.

9

It is home to a pink rattlesnake found nowhere else on Earth

The Grand Canyon Pink Rattlesnake has a pinkish-red coloring that matches the canyon's own distinctive rock walls so closely that it's nearly invisible. It is found nowhere else in the world. Officially classified as Crotalus oreganus abyssus , it has darker diamond-shaped markings along its back that deepen the camouflage further.

10

There's a village at the bottom: Supai Village

For over 1,000 years, the remote village of Supai has been home to the Havasupai Tribe, the People of the Blue-Green Waters. It is located an eight-mile hike from the rim, but sits roughly 3,000 feet deep inside the Grand Canyon.

The U.S. Department of Agriculture has called it the most remote community in the contiguous United States, and it has no automobiles and no road access. The only ways in are on foot, by mule, or by helicopter. It is also the only place in the United States where the postal service still delivers mail by mule train.

1

George Wilson (1830): The man who refused his own pardon

In 1829, George Wilson and his accomplice James Porter robbed a U.S. mail carrier in Pennsylvania. Both were convicted in May 1830 on six counts, including putting the carrier's life in jeopardy, and sentenced to hang within weeks.

Porter was executed on schedule. But Wilson's influential friends petitioned President Andrew Jackson, who granted Wilson a formal pardon in June 1830, saving him from the gallows. Then Wilson did something that had never happened before in American history: he refused it.

The case was so unprecedented that it reached the Supreme Court in 1833, housed at the Capitol in Washington, D.C., as illustrated above. Chief Justice John Marshall ruled that the pardon couldn’t be valid without acceptance. However, Wilson was never executed. He served his prison sentence and was eventually pardoned a second time by President Martin Van Buren in 1841.

2

Richard Nixon (1974): The only president ever pardoned

On the night of June 17, 1972, five operatives were arrested breaking into the Democratic National Committee offices at the Watergate complex in Washington, D.C. Investigations revealed that President Richard Nixon had known about the cover-up and actively participated in it. Facing near-certain impeachment, Nixon became the only U.S. president ever to resign from office, stepping down in 1974.

Just 30 days later, his successor Gerald Ford announced from the Oval Office that he was granting Nixon "a full, free, and absolute pardon" for all offenses against the United States committed between 1969 and 1974. No charges had even been filed. The decision was widely condemned. Many historians believe it cost Ford the 1976 presidential election to Jimmy Carter. Nixon accepted the pardon but never admitted criminal guilt, expressing only "regret" for how he had handled the situation.

3

Iva Toguri D'Aquino (1977): The woman they called "Tokyo Rose"

Iva Toguri D'Aquino was a Los Angeles-born 25-year-old visiting a sick relative in Japan when the attack on Pearl Harbor stranded her there in December 1941. The Japanese government declared her an enemy alien and coerced her into broadcasting on Radio Tokyo's Zero Hour program.

This was a Japanese psychological warfare strategy that utilized English-speaking women, eventually all referred to collectively as " Tokyo Rose," to broadcast demoralizing messages intended to weaken Allied troop morale. After Japan's surrender, journalists identified Toguri as one of the voices.

A jury convicted her of treason in 1949, and she was sentenced to 10 years in prison. She served six years. After a 1976 CBS 60 Minutes segment revealed key witnesses had lied, President Gerald Ford granted her a full and unconditional pardon in 1977, on his final day in office. It remains the only presidential pardon ever granted for a treason conviction in U.S. history.

4

Jack Johnson (2018): A champion pardoned 72 years after his death

John Arthur "Jack" Johnson was the first Black man ever to hold the world heavyweight boxing championship. In May 1913, a jury convicted him under the Mann Act (a federal law against transporting women across state lines for "immoral purposes") for traveling with his white girlfriend, whom he had since married.

Johnson skipped bail, fled to Canada, and fought two world title defenses in Paris before losing the belt in Havana in 1915. He surrendered to U.S. authorities in 1920 and served nearly a year in Kansas. He died in a car crash at age 68 in North Carolina in 1946.

After years of bipartisan lobbying and a call from actor Sylvester Stallone, President Trump signed Johnson's posthumous pardon in the Oval Office in 2018, 105 years after the conviction.

5

Samuel Mudd (1869): The doctor who set the assassin's leg

Hours after John Wilkes Booth shot President Abraham Lincoln at Ford's Theatre in Washington, D.C., one April night in 1865, Booth arrived at the Maryland farm of Dr. Samuel Mudd with a broken leg.

Mudd set the fracture and gave Booth shelter. When investigators linked Mudd to Booth, including through prior meetings in 1864, he was tried by a military commission and convicted of conspiracy. Sentenced to life imprisonment with hard labor, he was sent to Fort Jefferson, a remote military prison on an island 70 miles west of Key West, Florida.

In 1867, a deadly yellow fever outbreak killed the prison's doctor. Mudd stepped in, treating patients and helping contain the epidemic. A petition signed by 299 enlisted men and officers was sent to President Andrew Johnson praising Mudd's courage. Johnson granted Mudd a full and unconditional pardon in 1869. Mudd was released on March 8 and returned to his Maryland farm. His conviction was never overturned; the pardon freed him, but the guilty verdict stood.

6

Marc Rich (2001): A fugitive pardoned on the last day

Marc Rich was a billionaire commodities trader indicted in 1983 on 65 counts, including tax evasion, wire fraud, and trading oil with Iran during the 1979–1981 hostage crisis. Before facing trial, Rich fled to Switzerland, where he remained a fugitive from U.S. justice for 17 years.

On January 20, 2001, his very last day in office, President Bill Clinton granted Rich a full pardon, bypassing the standard Justice Department review process. T he pardon ignited one of the biggest controversies of Clinton's presidency. Rich's ex-wife Denise had donated more than $1 million to Democratic causes and the Clinton Presidential Library.

A federal investigation led by prosecutor Mary Jo White was launched but ultimately found no criminal wrongdoing by Clinton. Clinton's own Justice Department had recommended against the pardon. Rich died in Switzerland in June 2013 at the age of 78, never having returned to the United States.

7

Patty Hearst (2001): From kidnapped heiress to bank robber

Patricia Hearst, the 19-year-old granddaughter of newspaper magnate William Randolph Hearst, was kidnapped from her apartment in Berkeley, California, in 1974. She was taken by a radical militant group called the Symbionese Liberation Army.

After weeks in captivity, in which she was kept in a closet, blindfolded, she appeared in a bank surveillance video holding a rifle and participating in the robbery of a bank in San Francisco. She was captured in September 1975. Her defense argued she had been brainwashed and acted under duress. A jury rejected that argument, and she was convicted of bank robbery in 1976 and sentenced to 7 years.

President Jimmy Carter commuted her sentence in 1979 after she had served approximately 22 months. She was released and married her former bodyguard. In January 2001, President Bill Clinton granted her a full pardon in the final hours of his presidency.

8

Vietnam Draft Evaders (1977): The biggest blanket pardon in U.S. history

On his first full day as president in 1977, Jimmy Carter signed Proclamation 4483, granting an unconditional pardon to all Americans who had violated the Military Selective Service Act in the span of U.S. involvement in Vietnam.

The government estimated that approximately 210,000 men had been formally accused of draft violations , while hundreds of thousands more had never been charged. Many had fled to other countries, roughly 90% to Canada, where they had been welcomed as legal immigrants.

Carter had campaigned openly on the promise, calling it necessary to heal a nation still divided by the war. The pardon did not extend to military deserters. Veterans' organizations were furious. Despite the backlash, an estimated 50,000 of those eligible chose to remain in Canada permanently, never returning home.

9

Scooter Libby (2007 / 2018): The spy scandal at the heart of the White House

Lewis "Scooter" Libby served as Chief of Staff to Vice President Dick Cheney during the George W. Bush administration. In 2003, the identity of Valerie Plame (a covert CIA officer) was leaked to journalists, apparently in retaliation against her husband, former Ambassador Joseph Wilson, who had publicly challenged the administration's case for the Iraq War.

Though Libby was not charged with the leak itself, he was convicted in 2007 of four felony counts: obstruction of justice, two counts of perjury, and making false statements to the FBI. He was sentenced to 30 months in prison and fined $250,000. Later that same year, President Bush commuted Libby's prison sentence, calling it "excessive," but left the conviction, fine, and probation intact; he declined to grant a full pardon. Eleven years later, in 2018, President Donald Trump issued a full pardon, completely wiping Libby's record clean.

10

Roger Clinton (2001): The president's half-brother

Roger Clinton is the younger half-brother of President Bill Clinton. Roger was given the Secret Service code name "Headache" during his brother's administration. In 1984, Arkansas state police ran an undercover sting operation that caught Roger selling illegal drugs to an informant. He pleaded guilty in 1985 to charges of conspiracy to distribute drugs and served approximately one year in federal prison, completing his sentence in 1986.

14 years later, on his last day in office, President Clinton granted Roger a full pardon, clearing his criminal record. The pardon drew relatively little public outrage compared to the Marc Rich case.