This Day in History: May 15

1252: Pope Innocent IV issues the papal bull ad exstirpanda

In this controversial document, the Pope authorized the use of torture during the Medieval Inquisition to extract confessions from heretics. However, the bull also set limits on the type and severity of the torture that could be used.

1618: German astronomer Johannes Kepler discovers his "harmonics law"

Kepler's third planetary law states that the square of a planet's orbital period is proportional to the cube of the semi-major axis of its orbit. This law helped pave the way for Sir Isaac Newton's theory of gravity.

1718: James Puckle patents the world's first machine gun

The "Puckle Gun" was a flintlock weapon with multiple barrels that could fire round or square bullets. It was designed for use on ships to defend against pirate attacks, but never saw widespread use.

1841: First emigrant wagon train to make it to California leaves Independence, Missouri

Approximately 100 pioneers set out on the 1,730-mile journey to California in search of a better life. The journey would take them over the Sierra Nevada mountain range and through challenging terrain.

1869: National Woman Suffrage Association forms in New York

Founded by prominent suffragists Susan B. Anthony and Elizabeth Cady Stanton, the organization advocated for women's right to vote and played a major role in the women's suffrage movement.

1928: First Mickey Mouse film is screened

"Plane Crazy," a short film directed by Walt Disney, premiered featuring the iconic character Mickey Mouse. The film's release marked the beginning of a new era in animation and entertainment.

1930: First airline stewardess goes on duty

Ellen Church and her team served snacks and beverages on a United Airlines flight from Oakland to Chicago. They also had other duties, including refueling the aircraft, handling luggage, and checking tickets.

1940: Richard and Maurice McDonald open the first McDonald's restaurant in San Bernardino, California

Originally a drive-in barbecue restaurant, the McDonald brothers revolutionized the fast food industry by implementing an assembly line system that greatly increased efficiency and reduced costs.

1948: First Arab-Israeli War begins

Israel declared its independence on May 14, 1948, and the next day, Egypt, Syria, Transjordan, and Iraq invaded the new state. The conflict lasted for almost 10 months and resulted in thousands of casualties on both sides.

1951: AT&T becomes the first US corporation to have a million stockholders

After a young car salesman named Brady Denton purchased 7 shares worth $1,078, AT&T became the first US company to have a million stockholders. Today, the telecommunications giant remains one of the largest companies in the world.

1988: USSR begins withdrawing troops from Afghanistan

After a decade of fighting against Afghan rebels, the Soviet Union began pulling its 115,000 troops out of the country. The war had been a costly and unpopular conflict for the Soviet Union.