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10 Split-Second Decisions That Changed History

Whether you consider these choices oversight, instinct, or pure luck, what followed could have easily gone another way. Read on for scary proof that the future often hinges on seemingly inconsequential decisions.

Martin Luther King Dr. Martin Luther King Jr. acknowledges the crowd at the Lincoln Memorial for his "I Have a Dream" speech during the March on WashingtonAnonymous/AP/REX/Shutterstock

Four words that shaped America

On August 28, 1963, Martin Luther King, Jr. approached the podium near the Lincoln Memorial with something he didn’t normally need: notes. Sensing the importance of the moment, King had stayed up late the night before perfecting his speech. But as he delivered it, he came to a line that wasn’t quite right. Off to the side, the singer Mahalia Jackson shouted, “Tell them about the dream, Martin!” King paused, looked out over the crowd, and went off-script, saying, “I say to you today, my friends, even though we face the difficulties of today and tomorrow, I still have a dream.” The rest of the speech stayed on that theme and “I have a dream” went down in history as one of the most memorable phrases ever delivered. The identity of these 8 iconic figures remains a mystery.

Fidel Castro Fidel Castro bearded Prime Minister tells Cuban people in television and radio speech criticism by Eisenhower and Herter premediated to help form internal front against his regime on in Havana, CubaAnonymous/AP/REX/Shutterstock

Time zone confusion ruined America’s relationship with Cuba

In early April 1961, Cuban exiles were trained and ready to execute the CIA’s secret plan to attack Cuba’s Bay of Pigs and overthrow Fidel Castro’s socialist government. After a failed air strike, President Kennedy sent in six American fighter planes to help. But the pilots forgot to sync their watches to Cuba time and arrived an hour late, rendering them useless. The relationship between Cuba and America has been strained ever since. These are the most bizarre historical coincidences throughout history.

Portrait of Gen. Robert E. Lee, commanding officer of the Confederate ArmyREX/Shutterstock

A note that cost the Confederacy

During the invasion of Maryland in September 1862, Confederate General Robert E. Lee drafted Special Order 191, outlining the moves the Army should make in preparation for the Battle of Antietam. A copy of the order ended up in the careless hands of Maj. Gen. D.H. Hill, who forgetfully left the note in a box on the ground, wrapped around three cigars. Union troops found the order, read the plans, and fended off the South in the bloodiest battle—and a turning point—of the Civil War. If you’re surprised by how the Civil War ended, learn about these 18 history lessons your teacher lied about.

Cove Neck, New York: c. 1907 President Theodore Roosevelt seated in a chair outside his Sagamore Hill home on Long Island.Underwood Archives/Shutterstock

The lengthy speech that saved a president’s life

On the evening of October 14, 1912, outside the Hotel Gilpatrick in Milwaukee, Wisconsin, president Theodore Roosevelt folded a 50-page manuscript in half and slipped it into the breast pocket of the Army overcoat he was wearing. He was headed to an auditorium nearby to deliver a campaign speech. As he stood to wave at the waiting crowd, a man shot him pointblank in the chest with a Colt .38 revolver. Luckily for Roosevelt, the gun was aimed at the side of his chest protected by the thick papers of the speech. The wad slowed the bullet to prevent it from entering his lung, and he went on to deliver the speech. Read about these historical facts you wish weren’t really true.

Photograph of the launch of the Titanic, prior to being fitted out. Belfast. Dated 1911 (Photo by: Universal History Archive/UIG via Getty images).Universal History Archive/Shutterstock

The key to a titanic disaster

On the night of April 14, 1912, the watchman assigned to the crow’s nest post atop the Titanic had a problem. The binoculars he needed to keep an eye out for large obstacles (icebergs, say), were inside a locked locker—and the key was missing. Right before the ship left port, the cruise company made a last-minute decision to replace the ship’s second officer David Blair with Charles Lightroller. In his haste to make the switch, Blair forgot to hand over the keys to the locker. These presidential mysteries were never solved.

The Berlin Wall Seen From Bernauauer Street In The French Sector.Bill Cross/Shutterstock

The man who spilled the beans about the Berlin Wall

The collapse of the Berlin Wall was the beginning of the end of the Cold War, a monumental occasion in modern world history. And it was announced by accident. On November 9, 1989, Günther Schabowski, an East German Communist official, was addressing the media at a news conference when someone asked about travel restrictions. At the time, the wall prevented citizens in East Germany from traveling west. According to The Guardian, Schabowski hesitantly responded, “Therefore we have decided today to implement a regulation that allows every citizen of the German Democratic Republic to leave East Germany through any of the border crossings.” When pressed as to when the rule would take effect, he said, “Immediately, without delay.” This information wasn’t supposed to be released until 4 a.m. the next day, but it immediately spurred the collapse of the wall. It was one of the most important moments in modern history, unlike these 9 famous moments in history that never actually happened.

Normandy, France: June 9, 1944. American troops of the 4th Infantry Division at Utah Beach taking a breather before continuing the assault over the hill to the interior of France.Underwood Archives/Shutterstock

The vacation that led to D-Day

The invasion of Normandy on June 6, 1944, was arguably the most significant win for the Allies in World War II—and it could have ended much differently. German general Erwin Rommel, also known as the Desert Fox, was tasked with leading the defense at Normandy. However, he left his post a few days before June 6. Accounts differ on the reason for the departure, either to speak with Hitler in Bavaria or to be with his wife on her birthday (which, incidentally, was on June 6). Nevertheless, his absence is seen as part of the reason for Germany’s fall at Normandy—and the outcome of the entire war.

Matthew Paris English Monk and Historian 1200 - 1259Historia/Shutterstock

The monk who almost destroyed calculus

As students, we either loved calculus or hated it, but the world’s advancements in science in technology would be nothing without it. And if it weren’t for one nameless 13th-century monk, those advancements may have occurred a lot sooner. Apparently, this monk couldn’t find any fresh paper to write his prayers, so he decided to erase the contents of an ancient text written by Archimedes, the Greek mathematician, and used that. Scientists later determined that the text was from a previously unknown book, now called the Archimedes Palimpsest, that laid out foundations of calculus long before Sir Isaac Newton and Gottfried Leibniz, who are credited with discovering calculus.

Marie Antoinette Picking Flowers 1755 - 1793Historia/Shutterstock

Marie Antoinette’s fatal decisions

You know Marie Antoinette as the Queen of France who is famously credited with saying, “Let them eat cake.” (She never said this.) Something she did actually do was make a last-minute decision that destroyed all chances of her family escaping death. In 1791, Marie Antoinette and her husband, King Louis XVI, were planning a counterrevolution against French rebels and decided to flee Paris for Montmédy, near the Netherlands. General Francois-Claude Bouillé advised their family to take two carriages for the journey, Smithsonian Magazine reports, but Marie Antoinette insisted they travel together in a fancier carriage called a berlin. On their journey, some armed villagers recognized the carriage and overtook them. This capture was instrumental in their eventual executions. In addition to the famous phrase Marie Antoinette never uttered, find out 16 more history facts that everyone gets wrong.

Stanislav Petrov Former Soviet missile defense forces officer Stanislav Petrov poses for a photo at his home in Fryazino, Moscow region, Russia, Thursday, Aug. 27, 2015. On Sept. 26, 1983, despite the data coming in from the Soviet Union's early-warning satellites over the United States, Petrov, a Soviet military officer, decided to consider it a false alarm. If he had decided otherwise, the Soviet leadership could have responded by ordering a retaliatory nuclear strike on the United StatesPavel Golovkin/Shutterstock

The man who stopped nuclear war

Stanislav Petrov may not be a household name, but without him, there may not have been any households at all. The lieutenant for the Soviet Union Air Defense Forces was working an overnight shift in September 1983, when his computer showed that five U.S. missiles were heading toward his country. He could have immediately reported the missiles, which likely would have resulted in all-out nuclear war, but he didn’t. Something wasn’t right; why would the Americans only send five missiles? He checked the computer and confirmed it was a malfunction. NPR reports that that incident and the Cuban Missile Crisis are considered the closest instances of nuclear exchange between the United States and the Soviets—and the former was prevented by a single man trusting his gut. Now, find out about 11 of the biggest lies that made history.