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.
Theory of Phoenician discovery of the Americas
It is possible that Mesopotamian ships could have gotten lost and sailed to the Americas, and left artifacts near the coast which could be tested for their veracity. Positive evidence would suggest eastern explorers discovered the Americas long before the Norse exploration of Newfoundland c. 1000 CE.
In the late 18th century, a number of people speculated on the origins of the petroglyphs on Dighton Rock in Berkley, Massachusetts. Ezra Stiles, then President of Yale College, believed them to be Hebrew. Antoine Court de Gébelin argued in "Le Monde primitif" ("The primeval World") that they commemorated an ancient visit to the East Coast by a group of sailors from Carthage (modern-day Tunisia).