On May 15, 1991, the first episode of the popular animated television series 'The Ren & Stimpy Show' aired, which became a cult classic and significantly influenced the landscape of animated television.

May 15, 1988, marked the first official International Day of Families, established by the United Nations to promote awareness of issues affecting families.

The first-ever 'Watergate' break-in occurred on May 15, 1972, setting off a series of events that would ultimately lead to the resignation of U.S. President Richard Nixon.

On May 15, 1969, the first-ever human-made object, the Soviet spacecraft Luna 10, successfully orbited the Moon, marking a significant milestone in space exploration.

On May 15, 1940, the first-ever McDonald's restaurant opened in San Bernardino, California, setting the stage for a global fast-food empire.

On May 15, 1928, the first-ever solo transatlantic flight by a woman, Amelia Earhart, took place, solidifying her status as a pioneering aviator.