What if Britain declared war on the Union during the American Civil War?

RNG

Banned
What if the Trent Affair was not resolved? What if the two diplomats James Murray Mason and John Slidell were not released or perhaps some British citizens were accidentally shot in a dispute during the arrest? Britain would have to defend Canada and it's Caribbean islands first off and fierce sea battles would take place in Atlantic between Britain and the Union. Would British be able to fight them off? Would France join Britain in the fight against the Union? Who would win the war? What would the aftermath be? Most likely if there was a Southern victory there may be wars between the North and South for year afterwards, perhaps if World War One still happens the North side with the Central Powers and the South with Britain and France. Or if the North won perhaps the notion that the South will rise against actually happen and there may be another Civil War soon after the first. How would such a war change America, it's relationships to Europe, and history? What you think?
 

Philip

Donor
I've never bought the Trent Affair turning into a war, but I'll play along. I'll assume that the UK declares war in late 1861 or early 1862. At this point the Union is rather busy.

Britain would have to defend Canada

Not really. The Union is busy defending itself. It's not invading Canada.

fierce sea battles would take place in Atlantic between Britain and the Union.

The only fierce battle in the Atlantic will be the law suit Davy Jones files against the Royal Navy for littering the ocean floor with Union vessels. This is the middle of the Pax Britannica. The Royal Navy is unchallenged on the seas. The Union navy needs to focus on the CSA. They will not pursue the RN.

Would British be able to fight them

Yes. In 1862, the US is no match for the UK.

As for the rest, I don't buy a CSA surviving into the 20th Century. Nor do I believe the UK or France will favor the CSA once the war is over.
 
Last edited:
Britain would have been DEEPLY divided over such a war, especially after the Emancipation Proclamation. Oh and the invention of Ironclads just reset the naval power race, and industrialised US could have matched Britain
 

Onlooker

Banned
South could win in that case and would probably follow the suit of Brazil or similar states, in terms of slavery, keeping it for some time then abolishing it at a later date. It was simply an unsustainable practice. CSA could survive till modern times, mostly due to support of various great powers not eager in having a single hegemon over the America's. Union navy was no match for the British, therefore the blockade would fail. With South up in arms nothing more than small scale raids into Canada seems feasible. I think we'd see the war ground to a halt as Union sues for peace and hopes for a rematch at a later date when Britain is bussy, potentially WW1
 
Britain would have been DEEPLY divided over such a war, especially after the Emancipation Proclamation. Oh and the invention of Ironclads just reset the naval power race, and industrialised US could have matched Britain
But by 1865, the US Army woudl roll over Canada

The war, if it happened, would be quick and limited to naval actions unless the US was daft enough to invade Canada.

The casus belli was the stopping and removal of the Confederate envoys (and implicitly challenging the British assumption that its ships were inviolate, even in a "war zone")

A few short sharp naval actions and the bombardment of some forts would probably be the only immediate military action by the British. The impact of an economic blockade would have been far more damaging and unless the US came to terms quickly they would lose much of their fleet and much of their gunpowder production (through saltpetre imports from British India).

So my guess is if the war did come, it wouldn't last more than a few weeks until it was resolved. But those few weeks might significantly narrow the naval disparity between the Union and the Confederacy resulting in a very different war.
 
The world would be Wrapped in Flames...

Shameless plug aside though, a Trent affair only casus belli is hard, but the way you portray it (British citizens killed and all that) it could be done. There was an intense amount of misunderstanding in London about how politics in Washington were playing out, and they were ready to go to war over the issue historically. If British citizens were killed then the British would be harsh, and Lincoln would have little wiggle room to extricate himself from this tricky position.

However, he could negotiate it away at a steep price and he would mostly be willing to pay it.

Honestly it would take a little more than Trent to lead to a serious war. Lincoln has to be in a position where bowing to British pressure is largely untenable, the American public is in a volatile mood, the British don't trust American assurances, ect. It could be done, but would require some serious mishaps in the halls of Washington and London.

The course and outcome of the war is tricky, but you can probably count on two things:

1) The USN is completely driven from the sea by the RN and allows the Confederacy some much needed breathing space

2) The US is most likely distracted by funneling tens of thousands of troops to Canada and the coast to defend from British raids

All in all the war probably ends with Lincoln seeking a separate peace with Britain sometime before 1865, while the Confederacy is suddenly a much tougher nut to crack than historically. The biggest problem would be if Britain, in order to try and entice the Americans to the negotiating table, recognizes the Confederacy sometime in 1862-63. France follows suit, probably followed by Spain, the Low Countries, possibly Austria and Prussia.
 
But by 1865, the US Army woudl roll over Canada

The Union Army would be a vastly different beast by TTL's 1865, most likely having fought on more fronts than is healthy and suffered interdiction of its foreign arms and powder supplies. Merely keeping it at its OTL 1862 size will be something of a challenge for about a year while American industry gears up to supply it in a larger war and there's no guarantee that its morale and resolve holds that long or that Lincoln would even win election and continue the war here.
 
the UK has a rather unbeatable strategy to take on the Union... blockade the east coast. The USN just can't match the RN on the open seas, and the US in general is rather reliant on importing a lot of stuff.. particularly in 1862, when the Union couldn't even come up with enough modern firearms for it's armies. Depending on what the UK wants, Lincoln might seek terms pretty fast. If the UK just wants an apology and a promise that it's diplomats won't be arrested, then that'll do. If the UK wants an independent Confederacy or an end to the Union blockade, then there might be more trouble...
 
I have always found the idea of Britain somehow taking over the South interesting like if they agreed to back the Confederacy but only if they became part of the British Empire again they would protect them. Of course they have slavery and they have in that too and actually like joined as a Dominion but maybe they allow for some sort of, you know, gradual emancipation. Because one of the things I've heard about the conflict that it had largely to do with the fact that the people in the South or anglo-irish and this was really more about a war between that and the Germanic areas that the United States would become and it was a war between those two peoples at its core. So you know just be about them getting their heritage back to the country or whatever.
 
A few thoughts.

First of all, this is very unlikely aside from the Trent incident. And that could happen at peacetime or wartime, nothing to do with the civil war. The most likely outcome of Americans bugging the British is for them to simply demand a lift of the blockade.

If it does happen, America is toast. The South can sit out and watch popcorn since the British was mover powerful than North USA at this time.

"Wait, the British lost the ARW!" That required lots of hardships from the colonists. It was also dependent on the Patirots using civilians to hide among. In a war like this, the British can defeat American field armies and just sack cities, tear railroads, and destroy factories. In the ARW, they could try to defeat a Patriot field army, then go into a city and wonder who is traitor and who isn't
 
A few thoughts.

First of all, this is very unlikely aside from the Trent incident. And that could happen at peacetime or wartime, nothing to do with the civil war. The most likely outcome of Americans bugging the British is for them to simply demand a lift of the blockade.

If it does happen, America is toast. The South can sit out and watch popcorn since the British was mover powerful than North USA at this time.

"Wait, the British lost the ARW!" That required lots of hardships from the colonists. It was also dependent on the Patirots using civilians to hide among. In a war like this, the British can defeat American field armies and just sack cities, tear railroads, and destroy factories. In the ARW, they could try to defeat a Patriot field army, then go into a city and wonder who is traitor and who isn't

You do realize that American soldiers beat British armies in several open field battles during the ARW right? Saratoga comes to mind for one. The belief that the Americans won a partisan war and beat the British unfairly is an interesting myth. Without American battlefield victories in places like Trenton and Saratoga, the partisan war would have faded away.

A good analogy in the 20th Century to the American and British situation in the American War of Independence is the French Indochina War.
 
Before late 1863 = British Victory (and no US army standing alongside British and French forces against Germany's last offensive in 1918).
After late 1863 = 1812 type of stalmate.
 
It's true the Americans won pitched battles like Saratoga and a masterful ambush at Trenton. However, the British Army still had more fight in it and could destroy if it wanted to. Parliament turned down George III's demands to continue the war (raise another unit and more funds) not due to being lost militarily, but because it was sick of spending money. Without the partisan war, Burgoyne would have had a more secure line and not need to rush forward (and rushing bit him in the ass). More often than not, the Americans were forced to quit the field in the ARW against the regulars, and having the other side occupy your previous lines/positions is the definition of losing a battle.
 
Every single time this question is asked it devolves into "But no, Mom (England) is better!" and "But no, the U.S. is better!" Why must we go through this yet again?
 
It's true the Americans won pitched battles like Saratoga and a masterful ambush at Trenton. However, the British Army still had more fight in it and could destroy if it wanted to. Parliament turned down George III's demands to continue the war (raise another unit and more funds) not due to being lost militarily, but because it was sick of spending money. Without the partisan war, Burgoyne would have had a more secure line and not need to rush forward (and rushing bit him in the ass). More often than not, the Americans were forced to quit the field in the ARW against the regulars, and having the other side occupy your previous lines/positions is the definition of losing a battle.

chuckle, you might want to review all of the engagements of the Revolution
 
Every single time this question is asked it devolves into "But no, Mom (England) is better!" and "But no, the U.S. is better!" Why must we go through this yet again?

I am willing to move on myself

As to the impact of British Intervention, it really depends on when. Early period (Trent Affair up until mid 1863), potentially decisive. However once the Army of Northern Virginia has suffered catastrophic losses it cannot replace after Gettysburg, Vicksburg has fallen and especially after the Battle of Lookout Mountain, I just don't think the British can do much more than prolong the bloodletting.

It can be argued that prolonging the war might see Lincoln defeated in November 1864 but would it? A foreign invader might be just the thing to piss off Union public opinion enough to continue the war no matter the cost, particularly after the heavy losses in blood already suffered.
 
The other main point, aside from when do the British interfere, is WHY do they interfere?

A minor incident at sea after the Emancipation Proclamation is going to be a tough sell with the British public.
 
Top