Jackie Robinson, who had been playing with the Negro League team the Kansas City Monarchs, signs a contract with the Brooklyn Dodgers to become the first African-American major leaguer of the modern baseball era.

The Soviet Union detonates an experimental nuclear weapon called Tsar Bomba over the Arctic Circle, which, with a yield of 100 megatons of TNT, was then and remains today the most powerful weapon ever used by humanity.

Leon Czolgosz, the assassin of U.S. President William McKinley, is executed at Auburn State Prison in Auburn, New York by means of the electric chair. Czolgosz had shot McKinley twice with a cheap revolver and the President had lingered for several days before dying. After Czolgosz is executed, he is buried on prison grounds and sulfuric acid is thrown into his coffin to disfigure his body and result in its quick decomposition.

In Australia, Lindy Chamberlain is found guilty of the murder of her nine-week-old daughter. The baby was killed during a camping trip in the Australian interior. Chamberlain claimed a dingo had taken the baby, but a jury decided Chamberlain cut the infant's throat and buried her. The body was never found, but forensic experts played a large role in the conviction. Four years after the trial the baby's jacket is found inside a dingo lair, backing up Chamberlain's claim, and she is released from prison.

The U.S. Congress passes the Volstead Act over President Woodrow Wilson's veto, paving the way for alcohol Prohibition to begin the following January. The Act, named for Chairman of the House Judiciary Committee Andrew Volstead, was supposed to create a better society but instead helped lead to the rise of violent organized crime gangs. The law wouldn't be repealed until 1933.

During the second day of the event known as the March on Rome, Fascist leader Benito Mussolini officially takes control of the Italian government when King Victor Emmanuel III cedes power. Supported by a coalition of military, business, and right-wing leaders, Mussolini remains in power until 1943, when defeat in World War II begins to look inevitable.