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.
Tunnel Through the Deeps
In an alternative history, the United States lost the American Revolutionary War and George Washington was executed for treason. Thus, America in 1973 is still under the control of the British Empire. The divergence point between this world and our own occurred far earlier, however, when the Moors won the battle of Navas de Tolosa on the Iberian peninsula, on July 16, 1212. Thus it was that Spain was unable to become unified, owing to the survival of an Islamic presence in its territory, and therefore could not finance the expedition of Christopher Columbus in 1492. Instead, it was John Cabot who discovered America, just a few years later.