What prestige would there be in conquering Europe? Europe could offer neither the riches nor prestige that the Middle East, China, or India did. Compared to them, it was still a feudal backwater (on the whole).
I don't think that would be possible without a civil war happening. It's kinda hard to be both legally a citizen and someone else's property at the same time. I think it would be possible for the court not to deny citizenship to free blacks living in the North, but that doesn't help up a whole...
It probably wouldn't become a state until much later. The US didn't allow Hawaii to become a state (with a non-white majority) until the late 1950s. Likely, Dominica would remain a territory for a long time, while the standard of living rises and it become more assimilated (or not) into American...
Such an article wouldn't fly. The big states like Virginia and New York would not ratify a document containing a provision for sectioning themselves at an arbitrary limit without a pretty damn good rationalization.
Unless economic conditions in the South that drove many Italians to emigrate are majorly different, the number of immigrants should be relatively. However, I can see a much less restrictionist policy in the USA regarding Italian immigrants.
I PMed Leo about the linguistic effects of such a union a couple of months ago. Here's what he had to say:
If the Aragonese take Italy OTOH, it's reasonable for them to grow closer in language.
I thought it was Fibonacci who introduced Arabic numerals? Are you proposing that they never make it to Europe, or that the Europeans never adopt the numerals? If the later, you need to have them replaced by something more efficient. The truly clumsy system was the Roman one.