This sounds to me like the one I voted for, a regional confederation of sovereign states who are willing to work together towards a common goal - but not necessarily give up their own sovereign power. Minimum would be two such, everything north of the Maryland-Pennsylvania border, the rest south as a slavocracy plantation system. Possibly a third, the New England states (including Vermont).
I brought up the idea of regional confederations forming in - ironically - a recent thread that was specifically about the states remaining separate.
@Napoleonrules also participated in that discussion. If you'd like to read that, you can find it
here.
My thinking is that as soon as the Articles are there, it actually becomes very difficult to have utterly separate states, and (barring the adoption of the Constitution or something very much like it) it becomes more likely to either have the Articles revised (which is most likely), or to keep them as they are (which is less likely). And in that latter case, their flaws, combined with diverging regional interests, could well lead to regional confederations (and federations).
If there are no Articles to begin with, however, I'm less sure regional unification will catch on. Especially not in the sovereignty-minded southern states (...countries?)
If regional unification catches on, I see it catching on in the north first and foremost. Because it's good for business and industry when you hve a common market, a single currency, one system of weights and measures... etc. etc.
Do you think it is plausible we could see something similar to the slow growing pains of the European Union? A step or two towards cooperation, a step back, some states agreeing to do more together than others (such as common currency), even one of the states going through something similar to Brexit being a possibility (most likely either Rhode Island or Virginia for different and opposite reasons)?
Certainly
plausible! There are simply a lot of reasons why working together is just good for business. But any kind of unification is less
likely (at least in the short term) than it would be in any scenario where the Articles actually exist. Once they were
there, they became the basis of the debate. Union, of some kind, was a fact. Stepping out of that became a big jump into uncertainty, so the main question became "how close should this union be"?
But if sovereignty is the normal state of things, and there is no direct threat, the idea of unification is actually the scary leap into uncertainty. Keep in mind that the European unification only came about after horrors so gruesome were inflicted on the continent that basically everyone agreed "no war between us ever again". Even World War One was not enough to get people talking about unification seriously. Before the world wars, only a few fringe idealists advocated it, and even during the interbellum, it was only discussed by intellectuals and never became a policy goal of any government.
And inertia plays a big role. That's why leaving a union is difficult once it's there, and forming one is difficult because it's
not there. To change the status quo, something big needs to happen. In the USA, the doctrine of state sovereignty was only really abandoned after the Civil War. It's always a huge event or development that drives change on this scale.
If the states remain sovereign from the outset, and their union is only an alliance... what would drive them towards further unification? The longer they stay sovereign, the less likely one single union becomes. Soveignty will become more and more entrenched as an idea that one doesn't just mess with. Some states might integrate early on (common currency), but the very thought of it might lead others to bolt. Unless it happens after some great difficulty (like a war or other crisis) that leads many people to believe unification is
vital.
Personally, I don't see it happening until the whole deal with slavery is revolved. Because I don't see it happening
before that becomes a major issue. Once several states in the north have pretty much rejected slavery, as they did in OTL, they will become wary about the increasingly foreign slave states in the south. And those states will be wary of unification with the increasingly foreign northerners. I suspect the north would go for common currency and more regional integration (as I mentioned in that other thread). The south would be more wary, and if the idea came up, it would be in the form of a confederal union of their own, entirely apart from the north...
If they discuss it at all. Maybe they'll remain a bunch of mutually friendly countries, while the north slowly becomes a union not unlike the OTL (northern) USA. Maybe that union eventually gets tired of being in an alliance with slavers anyway, and just severs the treaty.
One alt-USA consisting of northern states, and a bunch of separate slave-holding countries to the south of it? Fairly soon, they won't even remember they considered themselves part of the same culture once.