I have only recently heard about an archaeological site in Newfoundland, Canada called L'Anse aux Meadows. At this site Norwegian archeologists Helge and Anne Stine Ingstad discovered a Viking settlement from the first decade of the second millennium. So what is the connection to Ireland? Among the Viking-age objects found at the site was an Irish ringed pin for fastening clothes.
In fact this archaeological evidence is perhaps tangible proof of the accounts of Irish involvement in Viking-age voyages in historical writings such as the Vinland Sagas. Academics have therefore surmised that the Irish language (along with Norse) may have been spoken in North America long before English or Spanish.
For more information on Irish involvement in Viking voyages see:
the-irish-role-in-the-viking-discovery-of-america