The Beatles made their first appearance on "The Ed Sullivan Show," watched by an estimated 73 million people.

The 25th Amendment to the U.S. Constitution was ratified, clarifying succession issues related to the presidency.

Nelson Mandela was released from prison after 27 years of confinement in South Africa.

Abraham Lincoln, the 16th President of the United States, was born in Hodgenville, Kentucky.

Boston Latin School, the first public school in what would become the United States, was founded in Boston, Massachusetts.

The St. Valentine's Day Massacre occurred in Chicago, where seven members of the "Bugs" Moran gang were gunned down, reportedly on the orders of Al Capone.

The USS Maine exploded in Havana Harbor, Cuba, leading to the Spanish-American War.

The tomb of King Tutankhamun was unsealed in Egypt by Howard Carter.

The House of Representatives resolved the Electoral College tie in the 1800 presidential election, electing Thomas Jefferson over Aaron Burr.

Pluto was discovered by Clyde Tombaugh at the Lowell Observatory in Arizona.

President Franklin D. Roosevelt signed Executive Order 9066, leading to the internment of Japanese Americans during World War II.

John Glenn became the first American to orbit the Earth, flying aboard Friendship 7.

Malcolm X, a civil rights leader and activist, was assassinated in New York City.

The U.S. Olympic hockey team defeated the Soviet Union in the "Miracle on Ice" at the Lake Placid Winter Olympics.

The Siege of the Alamo began in San Antonio, Texas.

President Andrew Johnson was impeached by the House of Representatives.

Hiram Rhodes Revels, the first African American senator, took his oath of office.

The World Trade Center in New York City was bombed in a terrorist attack that killed six people and injured over a thousand.

The 22nd Amendment to the U.S. Constitution was ratified, limiting U.S. presidents to two terms.

The Waco Siege began when ATF agents attempted to serve a search warrant at the Branch Davidian ranch in Waco, Texas.

(Leap Year) The first Playboy Club, featuring waitresses in "bunny" outfits, opened in Chicago.

President Abraham Lincoln issued the Emancipation Proclamation, declaring all slaves in Confederate-held territory free.

President Richard Nixon signed a bill lowering the maximum U.S. speed limit to 55 MPH to conserve gasoline during an OPEC embargo.

Alaska was admitted as the 49th state of the United States.

Utah was admitted as the 45th state of the United States.

Construction began on the Golden Gate Bridge; once completed, it became one of the world's most recognized bridges.

President Franklin D. Roosevelt delivered his Four Freedoms speech, outlining four basic freedoms for all people: speech, worship, want, and fear.

The first American commercial bank, the Bank of North America, opened in Philadelphia.

The Battle of New Orleans, a major engagement in the War of 1812, resulted in a decisive victory for the United States under Andrew Jackson.

Apple CEO Steve Jobs unveiled the first iPhone, revolutionizing the smartphone industry.

John D. Rockefeller incorporated Standard Oil, significantly influencing the petroleum industry and setting the stage for his future wealth and philanthropy.

President Theodore Roosevelt declared the Grand Canyon a national monument, preserving its natural beauty for future generations.

Hattie Caraway became the first woman elected to the United States Senate, representing Arkansas.

Johnny Cash performed his famous concert at Folsom Prison, recording a live album that would become one of his most celebrated works.

The Continental Congress ratified the Treaty of Paris, officially ending the American Revolutionary War.

Martin Luther King Jr. was born in Atlanta, Georgia. He would go on to become a leading figure in the American civil rights movement.

The 18th Amendment was ratified, prohibiting the manufacture, sale, and transportation of alcohol in the United States. It would later be repealed by the 21st Amendment.

President Dwight D. Eisenhower delivered his farewell address, famously warning against the influence of the "military-industrial complex."

President Thomas Jefferson requested funding from Congress to finance the Lewis and Clark Expedition, aiming to explore the lands west of the Mississippi.

The Apple Lisa, one of the first personal computers to offer a graphical user interface in an inexpensive machine, was announced by Apple.

Ronald Reagan was inaugurated as the 40th President of the United States; on the same day, Iran released 52 American hostages after 444 days in captivity.

President Jimmy Carter pardoned nearly all American Vietnam War draft evaders, some 10,000 of whom had fled to Canada.

The Supreme Court delivered its decision in Roe v. Wade, legalizing abortion in the United States.

The USS Pueblo, a U.S. Navy intelligence vessel, was captured by North Korean forces, escalating Cold War tensions.

Gold was discovered at Sutter's Mill in California, sparking the California Gold Rush.

Nellie Bly completed her round-the-world journey in 72 days, inspired by Jules Verne's "Around the World in Eighty Days."

The first European settlers, including a penal colony, landed in Australia at Sydney Cove.

Auschwitz-Birkenau, the largest Nazi concentration and extermination camp, was liberated by Soviet troops.

The Space Shuttle Challenger broke apart 73 seconds after launch, killing all seven astronauts on board.

President George W. Bush labeled Iran, Iraq, and North Korea the "axis of evil" in his State of the Union address, framing U.S. foreign policy following September 11.

Mahatma Gandhi was assassinated by a Hindu extremist in New Delhi, just months after India achieved independence from British rule.

The U.S. House of Representatives passed the 13th Amendment to the Constitution, abolishing slavery in the United States.

The Battle of Gettysburg, one of the most crucial battles of the American Civil War, began.

U.S. President Lyndon B. Johnson signed the Civil Rights Act into law, outlawing discrimination based on race, color, religion, sex, or national origin.

Israeli commandos executed a daring raid at Entebbe airport in Uganda to rescue 103 hostages.

The United States Declaration of Independence was adopted by the Continental Congress.

The National Labor Relations Act, which established the right of workers to organize and bargain collectively, was signed into law by President Franklin D. Roosevelt.

Althea Gibson won the Wimbledon championships, becoming the first African American athlete to do so.

Four conspirators in the assassination of President Abraham Lincoln were hanged, including Mary Surratt, the first woman executed by the U.S. federal government.

The Liberty Bell was rung to summon citizens of Philadelphia for the first public reading of the Declaration of Independence.

William Jennings Bryan delivered his famous 'Cross of Gold' speech advocating for bimetallism at the Democratic National Convention in Chicago.

Wyoming was admitted as the 44th state of the United States.

U.S. Vice President Aaron Burr fatally wounded former Treasury Secretary Alexander Hamilton in a duel.

The Medal of Honor was authorized by the U.S. Congress.

New York City experienced a blackout lasting 25 hours that led to widespread looting and disorder.

Gerald Ford, the 38th President of the United States, was born in Omaha, Nebraska.

President Richard Nixon announced he would visit the People's Republic of China, signaling a significant shift in U.S. policy toward Communist China.

The first atomic bomb, code-named 'Trinity,' was detonated in a test at Alamogordo, New Mexico.

Disneyland, the first of the Walt Disney amusement parks, opened in Anaheim, California.

Franklin D. Roosevelt was nominated for an unprecedented third term as U.S. president at the Democratic National Convention in Chicago.

The Seneca Falls Convention, the first women's rights convention, opened in Seneca Falls, New York.

Apollo 11 astronauts Neil Armstrong and Edwin 'Buzz' Aldrin became the first humans to walk on the moon.

The First Battle of Bull Run, the first major battle of the American Civil War, was fought near Manassas, Virginia, and resulted in a Confederate victory.

Wiley Post became the first person to fly solo around the world, completing the journey in 7 days, 18 hours, and 49 minutes.

Ulysses S. Grant, the 18th President of the United States, died in Mount McGregor, New York.

Tennessee became the first Confederate state to be readmitted to the Union after the Civil War.

Louise Brown, the world's first test-tube baby, was born in Oldham, England, through the process of in-vitro fertilization.

The United States Postal System was established with Benjamin Franklin as its first postmaster general.

The Korean War ended with the signing of an armistice agreement at Panmunjom, now in North Korea.

The 14th Amendment to the United States Constitution, guaranteeing due process and equal protection under the law, was ratified.

NASA was established by the National Aeronautics and Space Act signed by President Dwight D. Eisenhower.

The first legislative assembly in America convened in Jamestown, Virginia.

Apollo 15 astronauts David Scott and James Irwin rode in the Lunar Roving Vehicle for the first time on the moon's surface.

The Beatles released 'Sgt. Pepper's Lonely Hearts Club Band,' one of the most influential albums in music history.

U.S. President Calvin Coolidge signed the Indian Citizenship Act into law, granting citizenship to all Native Americans born within the territorial limits of the United States.

The poem 'Casey at the Bat' by Ernest Thayer was published in the San Francisco Examiner.

The Battle of Midway, one of the most decisive U.S. victories against Japan during World War II, began.

Robert F. Kennedy was assassinated in Los Angeles shortly after winning the California presidential primary.

D-Day: Allied forces landed on the beaches of Normandy, France, marking the beginning of the end of World War II in Europe.

Richard Henry Lee presented the Lee Resolution to the Continental Congress; it was the motion calling for the colonies' independence from Great Britain.

USS Liberty incident: Israeli fighter jets and navy ships mistakenly attacked the American spy ship USS Liberty in international waters during the Six-Day War.

During the Senate-Army Hearings, Joseph McCarthy was confronted by attorney Joseph Welch with the famous line, 'Have you no sense of decency, sir, at long last?'

Benjamin Franklin conducted his kite experiment, proving that lightning is electricity.

President John F. Kennedy delivered his famous Civil Rights Address, in which he proposed the Civil Rights Act of 1964.

President Ronald Reagan challenged Soviet leader Mikhail Gorbachev to 'tear down this wall!' in a speech at the Berlin Wall.

The U.S. Supreme Court decided Miranda v. Arizona, establishing the Miranda rights of criminal suspects.

The Continental Congress adopted the Stars and Stripes as the official flag of the United States.

George Washington was appointed commander-in-chief of the Continental Army by the Second Continental Congress.

Abraham Lincoln delivered his House Divided speech at the Illinois State Capitol in Springfield.

The Watergate scandal began with a break-in at the Democratic National Committee headquarters at the Watergate complex in Washington, D.C.