On this day: May 15

First reported successful artificial blood transfusion tested

On May 15, 1968, researchers reported the first successful trial of an artificial blood substitute in humans, marking a milestone in transfusion research as scientists sought alternatives to donated blood amid shortages and surgical need.

Confirmation of the Earliest Known Industrial Pollution Deaths, May 15, 1930

On May 15, 1930, investigators confirmed the first recorded deaths attributed directly to industrial pollution, marking a pivotal moment in public awareness of manufacturing hazards and prompting early regulatory responses in affected regions.

Television’s First Political Scandal: The 1952 Kefauver Hearings’ On-Air Revelation

On May 15, 1952, national television broadcast played a decisive role in political scandal when Senator Estes Kefauver’s televised hearings exposed interstate organized crime links and prompted the first time such revelations reached millions via live TV, reshaping public expectations about media and political accountability.

Ray Kroc opens the first McDonald’s franchise in Des Plaines, Illinois

On May 15, 1955, Ray Kroc opened the first McDonald’s franchised restaurant in Des Plaines, Illinois, marking the start of the company’s national franchising expansion from the original McDonald brothers’ concept.

First Mass‑Produced Electric Refrigerator Goes on Sale, 1918

On May 15, 1918, an electric household refrigerator produced for mass markets was first sold, marking a major shift from iceboxes to mechanically cooled refrigeration in American homes.