"It's no news that American revivalists, drawing from English dance materials which had been collected and disseminated by Sharp and his successors (and rivals), taught morris and sword dances at the southern settlement schools from the time of the First World War."

http://www.americanmorrisnews.org/pastissues/may2007v27n1/current_issue/stevecorrsinv27n1hoistingonthelockinamerica.html

I don't know how definitive this quote is, but it suggests there may have been no Morris (dances at least) in the US before the Sharp revival.