Been thinking of a potential scenario involving Italian and Swiss Italian colonization of North America, in which one or more of the major Northern Italian states establish a successful colony in what is now the OTL Eastern United States in the late 1500's or early 1600's and this plays a major role in the cultural development of North America and the creation of the United States.
I'm thinking the colony would be in either North Carolina and extending into the Appalachian Mountains or have it be in New Jersey and then extending into upstate New York and Vermont at its apex.
Personally, I'm leaning towards the former and because of this colonial endeavor, the Scots-Irish do not successfully settle Appalachia or the Upland South and those that tried were driven out after being defeated in a bloody war in the 1700's, most likely during the chaos of the Seven Years War. Britain still wins the Seven Years War, but the Italian-Swiss colony in Appalachia acts as an effective buffer against British expansion for a while and the colonists side with the Anglo-American colonies in this timeline's equivalent of the American Revolution in exchange for keeping their autonomy.
Throughout the next hundred years or so, most of the colony is sold to the United States until a small core in the High Country of Western North Carolina is kept and retained by the Kingdom of Italy following the wars of Italian unification. World War I and World War II both happen largely as they did in OTL.
After the United States enters World War II, the colony is briefly occupied by units of the Virginia and North Carolina National Guard and after VJ Day, the United States and Italy enter an agreement similar to the one held between Britain and China over Hong Kong where the colony is semi-autonomous but remains under nominal Italian control for the next sixty years before then becoming officially part of the United States in 2005.