Did the Vikings really reach America, and how do we know?

Yes, and the proof is in the ground. At L'Anse aux Meadows, on the northern tip of Newfoundland, archaeologists found the remains of eight buildings made of sod over a wooden frame, with over 800 Norse objects and evidence of iron production. Carbon dating gives about 990 to 1050, and tree rings pin an exact year, 1021. It is the only undisputed site of pre-Columbian European contact with the Americas outside Greenland, almost 500 years before Columbus.

The discovery overturned an old guess. The sagas spoke of Vinland, and historians had long speculated that, if it meant 'wine-land', it must lie in a region of wild grapes, no farther north than Massachusetts. The Norwegian husband-and-wife team Helge Ingstad and Anne Stine Ingstad doubted that. They discovered the Norse buildings and led an international excavation from 1961 to 1968.

The tree-ring date comes from a 2021 study: it used radiocarbon analysis of three tree-ring samples and a spike in atmospheric carbon-14 in the year 993 to pinpoint 1021. The wood had been cut with metal blades, which the local Indigenous people did not have.

What was the site? Eleanor Barraclough suggests it was not a permanent settlement but a temporary boat repair facility, with no burials, tools, agriculture or animal pens, so the inhabitants likely left in an orderly fashion.