1

Harriet Tubman secretly worked as a Union spy

Most Americans know Harriet Tubman for her leadership of the Underground Railroad, but during the Civil War, she also became a Union scout and spy in South Carolina. Working with Colonel James Montgomery, Tubman gathered intelligence from enslaved people living behind Confederate lines near the Combahee River .

In June 1863, Tubman helped lead the Combahee River Raid, guiding Union gunboats through Confederate waters filled with hidden mines. The operation freed more than 700 enslaved people and made Tubman the first woman known to lead a major U.S. military mission.

2

Julia Child worked for the U.S. intelligence agency

Before becoming television’s most famous chef, Julia Child joined the Office of Strategic Services, or OSS, in 1942 during World War II. The OSS later evolved into the CIA. Too tall to enlist in the Women’s Army Corps, Child instead classified files and overseas communications in Asia.

One of her strangest assignments involved helping researchers develop shark repellent for Navy explosives and emergency rescue kits . The repellent used copper acetate and black dye to create an odor similar to a dead shark.

3

Benjamin Franklin conducted unofficial spy work in Europe

Benjamin Franklin was more than a scientist and Founding Father. During the American Revolution, he quietly acted as an intelligence organizer while serving as ambassador to France beginning in 1776 . Franklin cultivated secret alliances, intercepted information, and used coded correspondence to support the colonies’ fight against Britain.

Operating from Paris, Franklin built relationships with French officials and helped persuade France to support the American cause with money, troops, and naval power. Historians consider his diplomatic intelligence efforts essential to the American victory at Yorktown in 1781 and eventual independence.

4

Louisa May Alcott published thrillers under another name

Louisa May Alcott became a literary icon after publishing Little Women in 1868, but few readers knew that she had already written sensational thrillers under the pen name "A.M. Barnard." These stories featured revenge, hidden identities, forbidden romance, and dramatic crime plots that shocked Victorian audiences.

Alcott used a pseudonym because publishers often expected women writers to produce respectable domestic fiction. Many of her darker stories remained forgotten until scholars rediscovered them in the 1940s. Today, titles like Behind a Mask reveal a far more rebellious side of the beloved author.

5

Maya Angelou worked as San Francisco’s first black female cable car conductor

Long before becoming a celebrated poet and author, Maya Angelou made history in San Francisco during the 1940s. At only 16 years old, she applied repeatedly for a conductor job on the city’s cable cars after seeing an advertisement that excluded Black applicants .

Angelou refused to give up despite repeated rejection. She eventually became San Francisco’s first Black female cable car conductor in 1944. Years later, she described proudly wearing the blue uniform while working long shifts across the city before launching her writing and civil rights careers.

6

Dr. Seuss created classified wartime propaganda films

Before writing Green Eggs and Ham and The Cat in the Hat , Theodor Geisel, better known as Dr. Seuss, worked on wartime propaganda during World War II. Between 1943 and 1945, he joined director Frank Capra’s Signal Corps unit to produce military training films for American soldiers .

Geisel also drew political cartoons supporting the Allied war effort and criticizing fascism. Some of his films were classified during the war because they contained military training material. His animated work helped explain battlefield strategy and morale issues to thousands of U.S. troops overseas.

7

Babe Ruth once played an entire game with a fever over 102 degrees

In 1925, Babe Ruth became seriously ill during spring training and collapsed while traveling by train . Newspapers nicknamed the incident "the bellyache heard around the world." Reports from the time described Ruth suffering from a fever above 102 degrees while still insisting on returning to baseball activities.

Despite his condition, Ruth’s determination became part of baseball legend. The illness hurt his performance during the 1925 season, when the New York Yankees finished seventh in the American League. Even so, Ruth rebounded quickly and helped lead the Yankees to championships in later years.

8

Harry Houdini worked with police departments

Harry Houdini’s famous escape acts fascinated police departments across America and Europe in the early 1900s. Officers regularly challenged him to escape from handcuffs, prison wagons, and locked jail cells. Houdini often invited local police to inspect restraints before his performances began.

Beyond entertainment, Houdini also worked closely with law enforcement to expose fraudulent mediums and fake spiritualists during the 1920s . Using his knowledge of locks, hidden compartments, and deception, he publicly demonstrated how many supposed supernatural tricks were actually carefully staged illusions.

9

Frank Lloyd Wright hid a private apartment inside one of his buildings

Architect Frank Lloyd Wright secretly maintained a private apartment inside his famous Oak Park Studio near Chicago, Illinois. Built in the 1890s, the studio served as both his workplace and personal retreat while he designed many of his early Prairie-style homes across the Midwest.

The hidden living quarters allowed Wright to work late into the night and host select guests away from public attention. The building itself became one of the most important centers of American architecture, producing groundbreaking residential designs that influenced modern architecture around the world.

10

Muhammad Ali quietly funded humanitarian causes for years

Muhammad Ali’s boxing fame often overshadowed his enormous charitable work. For decades, Ali quietly donated money to hospitals, food programs, children’s charities, and international humanitarian efforts . Friends and family later revealed that many of his contributions were intentionally kept private.

In 1990, Ali traveled to Iraq during tensions leading up to the Gulf War and helped secure the release of 15 American hostages. He also supported global relief organizations and Parkinson’s disease research after his own diagnosis. In 2005, President George W. Bush awarded Ali the Presidential Medal of Freedom.

1

Bill Clinton

Have you heard of Bill Blythe? Probably not, but you definitely know who he is: Bill Clinton, the 42nd president of the United States.

Born William Jefferson Blythe III on August 19, 1946, in Hope, Arkansas, Clinton never knew his biological father, who passed away in a car accident three months before he was born. His mother, Virginia Cassidy Blythe, later married Roger Clinton Sr. At 15 years old, Bill chose to take the surname Clinton, adopting the name of the man who had raised him .

2

Lyndon B. Johnson

Have you ever heard of a baby who went three months without a name ? As unusual as it sounds, one US president began life exactly that way.

The future Lyndon B. Johnson was born on August 27, 1908, near Stonewall, Texas. But instead of naming their newborn son, his parents found themselves in a standoff. According to historical records from the Miller Center at the University of Virginia, his mother, Rebekah Baines Johnson, wanted to name him Clarence, while his father, Sam Ealy Johnson, wanted the baby named after himself. Unable to agree, they left him officially unnamed, and for the first three months of his life, he was simply "Baby Boy Johnson." The deadlock finally ended when his mother gave in, and the future president was named Lyndon Baines Johnson , honoring Lyndon Baines, a family friend admired by his father.

3

Ulysses S. Grant

The 18th president of the United States wasn't born with the name we all know. He was born on April 27, 1822, in Point Pleasant, Ohio, as Hiram Ulysses Grant. So where did the famous "S." come from?

The answer is a paperwork mistake. In 1839, Ohio Congressman Thomas Hamer nominated the 17-year-old Grant to the US Military Academy at West Point. Knowing the young man went by Ulysses and that his mother's maiden name was Simpson, Hamer accidentally wrote "Ulysses S. Grant" on the nomination. Grant considered correcting the error, but eventually gave up, for two main reasons. He disliked the initials of his birth name, "H.U.G.", so the mistake didn't bother him much. In addition, fixing it would have meant a mountain of paperwork that could have jeopardized his appointment to West Point. So he simply let the new name stand, and the accidental middle initial stayed with him for the rest of his life.

4

Harry S. Truman

Harry S. Truman may have one of the strangest stories on this list.

His first name, Harry, honored his maternal uncle, Harrison "Harry" Young. His middle initial, however, didn't actually stand for anything. Truman's parents chose the "S" to honor both of his grandfathers, Anderson Shipp Truman and Solomon Young, without choosing one name over the other. In other words, the "S" wasn't short for Shipp or Solomon; it was simply "S". Truman himself usually wrote it without a period, since it wasn't an abbreviation. But after he became president, his staff encouraged him to add the period in official correspondence because it looked more conventional. That's why today he's almost always remembered as Harry S. Truman.

5

Dwight D. Eisenhower

President Dwight D. Eisenhower is remembered for leading the nation through the Cold War and signing the Civil Rights Act of 1957. But there's one surprising detail about him that most people never hear.

The man we know as Dwight Eisenhower was actually born David Dwight Eisenhower on October 14, 1890, in Denison, Texas. Named after his father, David Jacob Eisenhower, he quickly ended up with a problem: there were now two Davids in the same household. To avoid the confusion, his mother, Ida, simply began calling her son Dwight instead. He went by his middle name as if it were his first for years, but the change didn't become official until he applied to West Point at age 20. Wanting his official records to match the name everyone already knew him by, he registered as Dwight David Eisenhower and made the switch permanent.

6

Gerald R. Ford

On July 14, 1913, a baby boy named Leslie Lynch King Jr. was born in Omaha, Nebraska, and 61 years later, he became the 38th president of the United States. If the name doesn't sound familiar, there's a good reason: he entered the White House under a completely different name.

Leslie Lynch King Jr. was named after his father. However, just 16 days after his birth, his mother, Dorothy, fled the marriage with her infant son to escape her abusive husband. Three years later, she divorced King and married Gerald Rudolph Ford, a paint salesman who raised the boy as his own. From then on, everyone knew him as Gerald Rudolph Ford Jr. , even though he didn't legally change his name until December 3, 1935, when he was 22 years old.

7

Ronald Reagan

Have you ever heard of "Dutch" Reagan? Perhaps not, but that was in fact the childhood nickname of Ronald Reagan, the 40th president of the United States.

Born as Ronald Wilson Reagan on February 6, 1911, in Tampico, Illinois, Reagan got his nickname from his father, who thought his newborn son looked like a "fat little Dutchman." The moniker stuck almost immediately. As a boy, Reagan embraced it so completely that, according to his autobiographies and records at the Ronald Reagan Presidential Library, he disliked being called Ronald and insisted everyone call him Dutch instead. That changed only after he arrived in Hollywood in the late 1930s, when studio executives convinced him that "Dutch Reagan" wasn't exactly leading-man material.

8

Jimmy Carter

Born James Earl Carter Jr. on October 1, 1924, in Plains, Georgia, and named after his father, the future president had been called "Jimmy" almost from the day he was born.

Over the years, the nickname became the name he truly identified with. So when he took the presidential oath in 1977, Carter broke with tradition. Instead of using his formal first name like all the presidents, he was sworn in as Jimmy Carter, becoming the first (and still the only) US president to take the oath of office using a nickname rather than his legal name.

9

John Quincy Adams

The second president of the United States, John Adams, is one of the best-known Founding Fathers. His name is instantly recognizable to most Americans, and that's exactly why his son made an important decision about what he would be called.

John Quincy Adams was born on July 11, 1767, in the North Precinct of Braintree, Massachusetts, an area that was officially renamed Quincy in 1792. The nation's sixth president and the first son of a president to become president himself carried a name with a story. He was named not only after his father, but also after his maternal great-grandfather, Colonel John Quincy, who was gravely ill when the baby was born. Although Quincy was originally a family surname, it became the baby’s middle name. As an adult, he embraced all three names, John Quincy Adams, helping distinguish himself from his famous father while honoring both sides of his family.

10

Grover Cleveland

Most people have never heard of Stephen Cleveland, but mention Grover Cleveland, and they'll know exactly who you're talking about. The thing is, they're the same person.

Born on March 18, 1837, in Caldwell, New Jersey, the future 22nd and 24th president of the United States was actually named Stephen Grover Cleveland. His father, a Presbyterian minister, chose the name to honor Reverend Stephen Grover, the first pastor of the First Presbyterian Church in Caldwell, where he was serving at the time. As he grew older, however, Cleveland made an unusual choice: instead of going by his first name, Stephen, he adopted his middle name because he simply liked the sound of "Grover Cleveland" better.

1

Raven Rock Mountain Complex

Image: Ilagam

Did you know that in the 1950s, the US government carved out a secret underground city that could survive a nuclear attack? It’s called an "underground Pentagon", and very much like Area 51, it is one of the government's most classified projects.

This military complex and nuclear bunker is located near Blue Ridge Summit, Pennsylvania, 768 feet below the ground. It’s protected by 23.5 ft thick 30-ton doors built on top of springs to survive the shock from a blast. Raven Rock has five buildings with 15 floors big enough to live and work. The base has everything it needs to keep running, like a cafeteria, a barbershop, water generators, and even a medical center.

2

SubTropolis

Image: mwewering

Below Kansas City, Missouri, lies the world's largest underground business complex. SubTropolis is a structure located inside a mine north of the Missouri River. It was carved out of limestone some 135 to 185 feet underground and covers a total of 55 million square feet.

Kansas City Chiefs founder Lamar Hunt built this subterranean city in the 1960s. It has offices, storage space, and even factories. Over 1,600 people work here every day, largely because SubTropolis remains cool all year, making it an ideal location for businesses. Fun fact: some of Hollywood’s most beloved masterpieces are kept here, including the original film reels of Gone with the Wind and The Wizard of Oz.

3

Underground Atlanta

Image: Ronny Sison

Underground Atlanta is a historic spot in downtown Atlanta, Georgia. It was built in the late 1800s, right after the Civil War, as a commercial district centered around the railroad. In the 1920s, viaducts were built and the streets were raised, creating a second level of streets, buildings, and shops.

During Prohibition, the abandoned underground space served as the best spot for speakeasies and juke joints. For decades, people forgot about the hidden city, but in the 1960s, it was brought back to life as a fun place for music bars and nightlife.

4

New York City Subterranean World

Image: Photographer: unknown, Public domain, via Wikimedia Commons

Under America’s most populous city, there's a whole hidden world. For example, beneath Little Italy and the Public Library, there are secret vaults. Beyond the subway millions of people use daily, there is City Hall station, opened in 1904 and closed in 1945. It's a hidden gem with stained glass and mosaics that you can still visit by staying on the 6 train past the last stop.

But that’s not all! There are trading tunnels in SoHo and old cattle tunnels in the Meatpacking District. Also, in 1897, there were mail tubes built around the city to send letters between post offices that operated until the 1950s. Some of these underground spaces go as deep as 800 feet!

5

Permafrost Tunnel Research Facility

Image: Paxson Woelber

A large part of the land in the northern hemisphere is Permafrost, so it makes sense that there is a research facility specially built to study it. The Permafrost Tunnel in Alaska is the best place to learn about frozen soil that's over 40,000 years old.

The long tunnel was dug from 1963 to 1969 to study how to build and mine in frozen environments. Inside the facility, scientists study ice, ancient plants, and even bones from animals like mammoths. The tunnel shows different layers of earth, uncovering frozen ground from different time periods that help scientists anticipate what might happen as the world gets warmer.

6

The Greenbrier Bunker

Image: Alex Holzreiter

The Greenbrier Bunker in White Sulphur Springs, West Virginia, is a secret underground facility beneath a luxury hotel that has hosted numerous US presidents and famous guests. It was built during the Cold War to protect the US Congress in the event of a nuclear attack. The bunker was designed to house all 535 members of Congress and their staff for a long time.

This classified underground facility remained a secret until 1992, when a Washington Post article exposed it. Today, visitors can take tours to see special rooms, blast doors, and decontamination areas.

7

The Caverns

Image: jymy duhomme

Would you attend a concert underground? If you travel to Tennessee is totally possible! The Caverns, formerly known as Bluegrass Underground, is a very cool spot in Grundy County, Tennessee. Lying deep in a cave 333 feet underground, this concert venue with natural acoustics is the perfect place for live music.

People come from all over to hear a variety of performances, especially Bluegrass music. The Caverns can accommodate up to 1,200 people standing up and are equipped with state-of-the-art sound and lights. The cave's cool and quiet atmosphere makes the experience extra special!

8

Crystal City Underground

Image: Gustavo Alejandro Espinosa Reyes

Beneath the neighborhood of Crystal City, near Washington, DC, lies a network of shops, restaurants, and offices. It opened in 1976 and was designed to feel like an old shopping village with cobblestone streets and antique glass windows.

The underground space covers 150,000 square feet and connects several buildings. It's a popular spot for office workers and visitors, especially when the weather is bad. Unfortunately, in 2024, the shops closed, ending their retail era. Yet, the underground walkways and connections to the Metro remain open for pedestrians.

9

Los Angeles Prohibition Tunnels

Image: Alpha Perspective

In the 1920s, during Prohibition, people had to find ingenious ways around the restrictions on selling and consuming alcohol. That's why they built about 11 miles of underground tunnels right under Los Angeles.

Many of these subterranean sites are now closed, but you can still find a few hidden entrances around the city. You can even go on a tour to explore the tunnels and learn about their secret history.

10

Havre Beneath the Streets

Image: Đào Việt Hoàng

After a big fire in 1904 destroyed Havre’s business district in Montana, many shops moved underground. They used the old steam tunnels to stay safe from fires and bad weather. For years, the tunnels were busy with people and stores, such as saloons, drugstores, laundromats, and even a brothel. But today it is completely silent.

Fortunately, you can still visit what is left of this hidden city to see old shops and learn how people stayed safe and worked over 100 years ago. It's like going back in time!

11

Cheyenne Mountain Complex

Image: See page for author, Public domain, via Wikimedia Commons

One of the safest places in the world is right here in America, more specifically in El Paso County, Colorado. Hidden inside a mountain, Cheyenne Mountain Complex was built in the 1960s to protect the US military from nuclear attacks.

The bunker stands under 2,000 feet of solid Granite, making it super strong and safe. It was once the command center for NORAD (North American Aerospace Defense Command). The complex has blast doors that weigh 25 tons each and can withstand a nuclear blast. It also has its own power, water, and food supply. People could survive there for months!

12

Forestiere Underground Gardens

Image: Levi Clancy, CC0, via Wikimedia Commons

A Sicilian immigrant called Baldassare Forestiere spent 40 years digging and building a series of subterranean structures by hand in Fresno, California. Inspired by Roman catacombs and old wine cellars, he created around 65 rooms, tunnels, and courtyards to escape the hot summer sun.

The Gardens have fruit trees, grapevines, fishponds, and even a chapel. Some of the trees are more than 90 years old! Today, Forestiere Underground Gardens is a Historical Landmark you can visit if you want to discover a true underground paradise.