In the course of a work gig, I lately read up on Leif Ericson. I have noted him before on this blog, a gloomy Nordic presence at the space banquet. His claim to fame is as the second to last person to discover America, proof that mighty voyages do not always have mighty results. (The connotations of 'mighty' depending, of course, on perspective.)
To recap the story, Leif was the son of Eric the Red - an even more unwelcome guest at the space banquet, since he founded the Norse colony in Greenland that ultimately failed, its life support technology overwhelmed by the Little Ice Age.
Leif heard that another Norse seaman had sighted land west of Greenland, bought the man's ship, and went to see for himself. He found a couple of rather bleak islands, then one that was a lot less bleak. He dubbed it Vinland.
Up until 50 years ago this whole story hung only on the saga accounts, glimpsed along with King Arthur and the Trojan War across the misty frontier between history and legend. Then archeologists dug at L'Anse aux Meadows, on the northern tip of Newfoundland, and found a Norse outpost.
Leif's colonization effort was shortlived - mostly due to short tempered Vikings - and it is not certain that a 'colony' was the intent, rather than a base camp for resource exploitation. A chance encounter at sea more than 300 years later indicates that the Greenland Norse were still sailing as far as one of Leif's intermediate islands, Markland (possibly Labrador) to gather timber.
In short, the entire Vinland episode was a matter of a small frontier settlement looking for additional resources to tap in neighoring regions, a process that would be repeated scores of times after 1492. Leif Ericson, like Christopher Columbus, had no idea that he was 'discovering America.' But Columbus did know that he was looking for a major trade route, one that if it panned out would bring fabulous wealth to Spain (and, from his Genoese perspective, poke one in the eye of the Venetians).
Leif Ericson was not looking for a major trade route, only a supply source for a remote settlement. The Greenland Norse were too few to exploit it, and no one else had any practical need for it. In space terms, Vinland was just one more outer-planet moon that turned out not to warrant follow-up missions. A great story in its own right, but not, after all, a story of failed discovery.