While true, those early expeditions only left marks of semi permanent settlement in "Vineland", or Nova Scotia. They were ultimately abandoned. The large migration of Scandinavians and Finns came hundreds of years later, you can read more below. Basically they came for economic opportunities in America, and many chose to come to the upper Midwest due to familiar climate and resources. They were heavily involved in trades such as mining.
The years between 1870 and 1930 are sometimes referred as the Great "Migration" of Finns into North America. In the 1870s, there were only 3,000 migrants from Finland, but this figure was rapidly growing. New migrants often sent letters home, describing their life in the New World, and this encouraged more and more people to leave and try their luck in America. Rumors began of the acres of land that could be cleared into vast productive fields and the opportunity to earn "a barrel of American dollars" in mines, factories, and railroads.
Most Finnish migrants had planned to stay only a few years in North America, and then to return to their native land once they had become rich.[citation needed] However, only about twenty percent of the migrants returned to Finland.
https://en.wikipedia.org/wiki/Finnish_Americans#The_Great_Migration_(1870%E2%80%931930)