There was a stone inscribed with runes found in (I think) Pennsysvania in the 19th century, but that has been shown to be a fabrication (the language is wrong for its suppposed date of origin).
However, the remains of a Viking village have been found and excavated somewhere in Nova Scotia or thereabouts, so there's no doubt that there was at least one small settlement. (I don't have the details to hand at the moment, the book's at home - more later)
IIRC, the Vinland saga has a quite reasonably accurate description of the native tribe that the voyagers would have encountered, so with that and the actual physical evidence of a village, it seems that they did make it over the Pond...