In 1825, a ship carrying Norwegian colonists arrived in the United States, marking the beginning of modern immigration to America from Norway. This was celebrated with the Norse-American Centennial in 1925, and President "Silent Cal" Calvin Coolidge reminded in his speech of the earlier Scandinavian settlements led by Leif Erikson of Greenland. Learn more here.
The great (and literate) Scandinavian seafarers traveled all around the northern hemisphere during the Viking heyday, colonizing Iceland and Greenland, governing in Russia, and settling (as well as pillaging) the British Isles and Ireland. Their visits to Ireland, Scotland, England, and Wales exposed them to Christianity, which they embraced with recognition that it fulfilled the old religions and made real the hope of Heaven foreshadowed in the old stories.
During a voyage west of Greenland, Bjarni Herjolfsson had seen a new land, but had not stopped to explore. This created legends for young men to dream of exporing, and our hero Leif Erikson
did just that about 10 years later, buying Barney's boat, and setting off to see for himself.
The rest, as they say, is history. Leif created settlements at several locations on the Northeastern coast of North America before returning to Greenland to evangelize there.
Much of the original story, translated from the Sagas into English, can be found here to read for yourself: http://www.bartleby.com/43/1.html
Leif Erikson Day was adopted nationwide in 1963 and is celebrated on the anniversary of the arrival of the ship Restauration bringing the first modern-day Norwegians to their new life in the US "melting pot": October 9th. The Leif Erikson International Foundation website has excellent information if you'd like to learn more: http://www.leiferikson.org/index.htm