Thank you for the discussion,
Johnrankins, which is getting very interesting.
Sorry, I really wasn't clear here. These alliances happen AFTER the war. The US is already defeated but looking for allies.
Thank you for the clarification. There are still some problems, however. The Prussian-dominated nation of North Germany (whether it's still called the North German Confederation or it's renamed itself the German Empire or something like that for nationalist reasons, I don't know) will be deeply hostile to Austria-Hungary (presuming that Austria-Hungary falls IOTL) over the southern German states, just as Russia and Austria-Hungary were hostile over the Balkans IOTL except even more fiercely, because in this scenario North Germany will be fighting for the very unification of the German nation and the Habsburg empire will be fighting to maintain the sphere of influence which it has held for centuries.
With Austro-North German enmity virtually unstoppable in this scenario, as Franco-German hostility was since 1871 IOTL and Austro-Russian hostility was since 1876 IOTL, we must imagine the future alliance system around that. The reasons for the Franco-Russian Alliance don't exist in this scenario, so if it happens it must be for different reasons. Austria-Hungary may or may not clash with Russia, depending on whether it gets a Balkan focus when in this scenario, unlike in OTL, it retains its old focus in southern Germany. Still, with Serbia focusing pan-Serb expansionist claims against Austria-Hungary, Austria-Hungary might well clash with Russia, so let's say, for the sake of argument, that they do clash. In that case, North Germany and Russia will be together against Austria-Hungary and presumably the Ottoman Empire (which will be on the opposite side to Russia in virtually any plausible scenario unless it has a PoD before the 18th century, or maybe even further back). The UK will probably side against Russia, so (if the UK and the French Empire are on the same side) that puts the UK and France on the side of Austria-Hungary, the independent southern German states and the Ottoman Empire.
So, with that incredibly basic and questionable-assumption-filled summary (which can be refined far further if this scenario is carefully worked out in lots of depth), I predict that this scenario's *WW1 (presuming that it has one, by the OP) will be the UK, the French Empire, Austria-Hungary, the independent southern German states, the Ottoman Empire and the CSA against Russia, North Germany and the USA.
Come to think of it, this is beginning to sound extremely like
English Canuck's
A History of the Great War, though in that one the UK hasn't picked a side yet.
The Trent Affair is a real long shot, I know. You have to hand the idiot ball to Lincoln and Palmerston as neither was in the least bit interested in war. But with enough massive stupidity on both sides following a violent altercation when the diplomats were seized it is possible. It was the only thing I could come up with.
If I were you I'd take a look at
TFSmith121's
Burnished Rows of Steel, if you haven't already. It's noteworthy, though, that even in that scrupulously researched TL he/she is finding it difficult to actually make it come to war.
Alternatively, you could go for an earlier PoD. The American Civil War
in some form is fairly difficult to avoid because of the vast differences between the North and the South, the ideologies developing behind them and the North's rising population advantage, but if Lincoln were too competent to be comfortable with going to war against the UK in the middle of the Civil War (which I think is a justifiable statement) then perhaps it would be best for this scenario to have the US President be someone other than Lincoln.
Germany may or may not be unified the same exact way but I think it will be unified sooner or later and largely along the same lines. German unification was nearly inevitable since the Napoleonic Wars and the Germans were divided between Germany and AH mostly among religious lines that won't change in TTL.
Germany is a particular area of interest of mine, and I'm afraid I have to disagree on this point. The German states were not only divided by religious lines (the Kingdom of Württemberg was mostly Protestant but it held out with the likes of Catholic Bavaria) but by the lines of occurrences in the Austro-Prussian War, not just in the peace treaty that ended it but also in actions after it influenced heavily by it. The Austro-Prussian War is unlikely to be changed by a likely PoD here, but what happens afterwards is. The main cause for the unification of the North German Confederation with the remaining German states (except the Habsburg state) to form the German Empire was that the remaining German states were terrified of German lands being invaded by an aggressive French Empire (they remembered Napoleon I) and their worst fears seemed to be confirmed by a hilariously stupid misstep by Emperor Napoleon III (so stupid that many people on this website would probably call ASB if they didn't know it actually happened) so they signed a treaty that said they would come to Prussia's aid if Napoleon III played into Bismarck's hands, took the bait and attacked Prussia, which of course IOTL he did.
Get Napoleon III fixated on North America and busy there, and he won't have the time or attention to go fooling around in Central Europe. Take away Napoleon III's error and you take away King Wilhelm I's alliance with the remaining German states outside the North German Confederation (the Kingdom of Bavaria, the Kingdom of Württemberg, the Grand Duchy of Baden and the part of the Grand Duchy of Hesse that wasn't part of the NGC, as opposed to the part of the Grand Duchy of Hesse that was part of the NGC and the various different Hesses—Germany is complicated). Take away that alliance and you take away Bismarck's reason to deliberately trigger the Franco-Prussian War at the time he did. Take away that and you take away the fact that Austria-Hungary is still busy rebuilding and unable to fight… and you might well take away the Franco-Prussian War. Either way, give France extra experience fighting in the American Civil War and it'll learn a few bloody lessons and then it won't do so incredibly awfully in any Franco-Prussian War even if such a war somehow occurs.
As far as Russia is concerned I am shamelessly using butterflies. Again a longshot BUT possible.
I suppose this comes down to a difference of opinion on 'strong' and 'weak' butterfly theory; I can accept butterflies changing fairly random events in countries where they have had very major influence (e.g. if a war goes very differently, a future epidemic is unlikely to be the same, due to differences in movement of people). But in regard to deliberate acts of national policy by individuals born and influenced before the PoD, I'm of the opinion that any major difference from OTL should be justified
either by a direct chain of logic leading back to the original PoD
or by an explanation that the event was dependent on some variable that can reasonably be explained to be random.
Changing the tsarist state isn't easy; Aleksandr II was a reformer but Aleksandr III (born and raised before any likely PoD you might use) was knowingly reactionary and raised his son to be ignorant and unable to change anything for his whole youth (so either Aleksandr III stays in power, in which case there's a reactionary emperor, or Nikolay II takes over, in which case there's a reactionary regime left over and an incompetent emperor), so if you want reforms you probably need Aleksandr II, for the pre-WW1 era. One clear difference from OTL will actually be very bad for Russia; Aleksandr II's useful military reforms were shaped, to a great degree, by Prussian inspiration after the Franco-Prussian War, where Prussia had impressed the world with its swift, unexpected and total victory. If the Franco-Prussian War doesn't happen (and given Bismarck's personal role in bringing it about deliberately, he may well not do so if Prussia isn't in its OTL position where the southern German states have an agreement to come to Prussia's aid if France attacks, which they probably won't be in this scenario because of less fear of France) then that is very bad for the Imperial Russian Army.
The trickiest part, I admit. The US has far more to offer the UK and wouldn't be a complete slaveowner's paradise that the CSA would be. However, if there is enough bad blood stirred up and the US is steamed that it won't make up with the UK even if the UK offers to cut its alliance with the CSA (Damn unlikely but it might happen for US domestic political reason) then it might have little choice.
That's probably your best bet for a maintained Anglo-Confederate alliance: make the Union so objectionable that even the Confederacy somehow seems better. Even then, it will never be a comfortable alliance; think OTL's Anglo-Russian Convention (the British did their best to pretend that they were only fighting beside France and Belgium, and the British and Russians constantly clashed over various issues and it was nearly about to dissolve when the First World War interrupted the process) rather than OTL's Anglo-French
entente cordiale (which was genuinely fairly cordial, with very little tension after it began except for one major burst when it looked like the UK might not enter the war).
Annexed? Yes. Quickly? Maybe. It really depends on how militarized both nations are and if the CSA is able to get enough weapons/supplies from the UK. There aren't any tanks yet so the conquest can happen only as fast as a walking pace.
If the Union launches a huge military build-up fairly early, then the UK can't compete by the 1910s—or, to be more precise, it can't compete with the Union in North America and with whichever foe it has in Europe at the same time. The Confederacy will be a naval non-entity; like OTL's Japan in that period, it will have battleships as the UK (or maybe France) chooses to sell them some (or, later on, to officially let the Japanese make them but actually have most of the components pre-made in the UK), though perhaps not
quite as nearly-100% dependent as Imperial Japan was on the UK before the First World War IOTL.
Give the UK no enemy in Europe capable of matching its naval strength, however, and it might focus on North America.
The problem with the CSA is that it doesn't have the enormous industry that OTL's France used to throw back the German war effort and maintain a huge industrial war (albeit with lots of British money to make them able to do it). The Union could play that role, but the Confederacy couldn't.