It might work, but truth is that with Napoleon leaving the Elba for a last glorious ride the powers got a scare and decided it was time to put down the sword.
This was relatively easily done when they were still playing brinkmanship about the Polish-Saxon issue. However, if they have already fully committed to war once Napoleon escapes, making an hasty peace and a new anti-Napoleonic united front becomes rather less easy. A three-way war becomes a quite plausible outcome.
OTOH, prior to the Napoleonic escapade Talleyrand was doing his best to keep everyone at the table and avoid Alexander to leave Vienna in a huff IIRC,
Well, I have never made the Congress of Vienna PoD explicit in detail. It might well be killing Talleyrand off with a stroke or accident, I loathe the guy, he was amongst the main causes of getting the Bourbons back in charge twice.
and it's quite likely that the Saxon and Polish questions would not have been resolved without bloodshed.
Good on my TL.
Agreed on the 1814 POD, but not about the potential: Murat was a dobermann on two legs (and with the same cranial capacity of a dobermann)
We have to build with what history offers. I'm not sure which butterflies in the Napoleonic Wars it might cause to give Murat bigger brains. I guess I shall have to do with him getting an epiphany when the powers come to blows (he had one about letting Nappy sink in 1814, so it's not outlandish), and attracting some good counselors once he sets himself as a believable leadership for the Italian liberal-national movement (just like the way OTL Piedmont started attracting all the Italian best and brightest after 1848).
Very stretched. The USA have just come out of a mega civil war, the French are tromping all over Mexico, the Indians have taken advantage of the ACW to take back their lands and with all these issues on their plate the USA go and try to pick a fight with the British over a few paltry Fenian raids? To get a huge piece of empty (and apparently valueless) land?
I heartily disagree about the suggested lack of value for western Canada in American eyes. They were nowhere so disinterested about getting Columbia in the Oregon crisis, and both it and the Red River region attracted a sizable numer of American settlers.
I see your point about the USA being wary about a fight with Britain soon after the ACW (however, the British shall be equally wary of picking a fight with the USA after the Union Army made such a good performance).
However, I'm fairly determined to make the US purchase of western canada in 1866-67 an integral part of the TL at this point. I propose you two other PoDs for that: either the US offer to buy western Canada in exchange for dropping the Alabama claims, or the Fenian Raids are somehow more successful on their own, and the US government offers to suppress support fro them on their side of the border in exchange for UK acceptance of US purchase of western Canada.
Might be; I cannot believe it will be larger than OTL.
Equal to OTL is well enough to populate American western canada as well as Alaska and later northern Mexico, and the Dominican Republic, Cuba, and Puerto Rico were fairly populated on their own.
Well, assimilated if they allow/accept the assimilation to take their course; otherwise they will become second class citizen. Something like the fate of the Mormons IOTL as compared with the same in the infamouse Turtledove series.
Turtledove hugely exaggerates the ability of a tiny religious minority entirely surrounded by US-loyal immigration to remain defiant for decades IMO. Likewise, Quebecois emigration (part going to western Canada, part to the rest of the USA) is soon going to realize that America is no more friendly to Boulangist Popism and French-Canadian nationalism than Anglo Canada. As I do not see them going to take the total-isolation road of the Amish, nor they have the numbers to become a major player in the American political system on their own like Southern foundamentalism (which is going to be radically hostile to "Popism"), I see them eventually reluctantly accepting assimilation rather than permanent second-class citizen status.
I do agree that the positioning is a toss up. I'm just a bit more sympathetic toward the Argentinians

the fighting along the rio de la Plata and in Uruguay should be fierce.
Wholly agreed on this. Which chunks do you see US/AES-friendly Argentine getting at the peace table after the Great War ? IMO Uruguay, Rio Grande do Sul, Santa Caterina, are a given, but can we expect Buenos Aires to grab Paraguay, Paranà, and Igacu/Mato Grosso do Sul, too ?
Germany and Italy would certainly look the other way, what with the popist superstion of TTL Irish. I think there might be a significant Irish diaspora, maybe toward other land who are still majority papist-catholics (Venezuela, Colombia, Peru, Brazil)
I wholly agree with this. Given the Boulangist-Popist loyalties of the Irish, Germany and Italy are going to be wholly hostile to their cause (much like the attitude of Western Europe to Serbian nationalism in OTL 1990s, I'd say).
We've however an issue to settle with the Spanish situation: I don't want an Amadeus of Savoy king of Spain for just a few years and then abdicating.
I share your concern, and Amadeus has a more promoshing throne waiting for him in Bosnia in a few years anyway.
OTOH, the Cortes in the late 1860s/early 1870s have a progressive majority (probably not a good description: I've the feeling that the cohesion of the progressives was less than perfect). However, I believe that we should either delay the dethronement of Isabela by one year or two, or alternatively assume an earlier and stronger Carlist insurrection: this could result in a Spain more preoccupied with its internal situation than looking for a foreign king and might open the door for a Carlist compromise after say 2 or 3 years of bloody civil war.
I'm interested to have the Carlist pretender still without a throne until after the comte de Chambord becomes king in France.
Hmm, the second option might get in the way of getting a Carlist takeover after the Bourbon regime change in France, even stubborn Carlists might lack the energy to stage yet another coup or insurrection if they got a bloody nose a few years before. So I think the best option might be to delay the dethronement of Isabela a few years. It might be a butterfly arising from the I-F-G war. Let's say that some of the liberal generals that would later overthrow Isabela II delay their support to the revolution out of concern to the war raging on their northern borders. Soon after the war ends, they implement the revolution, but by that time, Pius IX has already escaped to France and is rousing reactionary Catholic opinion against liberalism across Europe. Tensions from the second Western Schism give the Carlists more following in Spain, so the Cortes get locked about choosing a new king. Soon after Chambord takes over, he pours French support to the Carlists, and they get the upper hand in a quick coup/insurrection.
BTW, I commend your valid effort to cross-pollinate the nice "Italy fulfilled" TL with ideas borne out of our own TL. Good work.
