Leif Erikson
Leif Erikson or Leif Ericson ( 970 – c. 1020) was a Norse explorer from Iceland. He was the first known European to have set foot on continental North America (excluding Greenland), before Christopher Columbus. According to the Sagas of Icelanders, he established a Norse settlement at Vinland, tentatively identified with the Norse L'Anse aux Meadows on the northern tip of Newfoundland in modern-day Canada. Later archaeological evidence suggests that Vinland may have been the areas around the Gulf of St. Lawrence and that the L'Anse aux Meadows site was a ship repair station.
Earth-Three
Earth-Three was introduced by Gardner Fox and Mike Sekowsky in a 1964 issue of "Justice League of America". Earth-Three's history is depicted as a mirror image to that of the Earth we know. On Earth-Three, Christopher Columbus was American and discovered Europe; England (a colony of America) won freedom in a reversed form of the Revolutionary War (with George Washington surrendering his sword to Charles Cornwallis) in 1774; President John Wilkes Booth was assassinated by actor Abraham Lincoln. Crucially, Earth-Three was home to an analogue to the Justice League, the Crime Syndicate of America.