Leif Ericson's voyages were paid for primarily by Olaf I Tryggvason, the Norwegian king. King Olaf commissioned Ericson to sail to Greenland in 1000 A.D. in order to spread Christianity to the people there.
Ericson ended up traveling not only to Greenland but also taking a detour (though it is not known whether it was accidental or planned) and ending up in modern day Nova Scotia. It is therefore believed that Ericson was actually the first person from Europe to touch down on North American soil. This was well before Christopher Columbus came over to North America nearly five centuries later. Ericson never returned to North America, however, and he did not colonize the area.