On This Day in History

Sunday, December 20, 2026

Captain America makes his first appearance

1940

The superhero Captain America made his first published appearance in the comic book Captain America Comics #1. (Captain America Comics)

1951 EBR-I produces electricity from nuclear power — Experimental Breeder Reactor I, near Arco, Idaho, became the world's first electricity-generating nuclear power plant, lighting four 200-watt bulbs.
1999 Macau is transferred to China — Portugal transferred sovereignty over Macau, which it had administered since the mid-16th century, to China.

Events from Wikipedia’s On This Day list, CC BY-SA 4.0. See also the Library of Congress essay Today in History.