At first, the North will think it's about eight different levels of fucked. However, this means things look a hell of a lot different. Let's say the war ends in, I don't know, 1863, and the reason the South wins is that the British helped them under the guise of "we'll free the slaves of you help us secede pretty please with a beneficial trade agreement on top." So the British help - and surprise surprise, the South kind of forgets about freeing the slaves, and the British kind of forget about the trade agreement, so the Confederacy and the U.K. start giving each other the stink-eye from overseas while the Union is about as pissed off at the Brits as can be - fighting three wars with varying outcomes will do that.
So the Union regroups. It moves its capital, finally settling on the shores of Chicago after the Great Chicago Fire, essentially splitting the city into a federal district and the Illinois section. (My expected POD would be that the Baltimore Plot succeeds, Lincoln isn't there to prevent anything from Maryland joining the South to the British interfering, Hamlin fucks everything up, and D.C. ends up in Confederate hands.) The Union passes a few amendments to the Constitution, one called the Lincoln amendment that defines presidential succession and includes everything from protection of the President-elect to succession from Election Day to the day of leaving office, and furthermore it makes the President's term start on the same day as Congress' terms just to prevent a long period of the President-elect waiting around to be shot at before taking office. So the Lincoln amendment is number 13 and it's a handful.
Next up is an amendment banning secession, possibly putting in a really difficult escape clause. Next up slavery is outlawed, because Kentucky, Missouri and WV have slaves and the Union really fucking hates slavery. Next up is the equal protection amendment applying to the states, because this makes the former slaves citizens as kind of a "look at how much better we treat our blacks here, you dirty Southern assholes" measure - even if the Union is decidedly racist, it's hard to see blacks being looked at as that different from any other ethnic group after a while, given that there's about to be a fuckton of immigration anyway and ethnic strife is as old as humanity, let alone America, so the end of the stick black folks get is shitty but not as shitty as OTL and they share that burden with Irish folks, Jews, Asians, and maybe even Italians. Finally the Voting Rights amendment. And since it's about to become necessary, the income tax amendment.
The USA's saving grace is the Industrial Revolution. The already largely urban North will be rife with industry seekers and possibly even defectors from the South. Escaped slaves will seek out jobs in factories, and when industry reaches the South, all of a sudden slave owners are going to go bankrupt with these now useless human assets - unless they turn their plantations into "company towns" and take a cut of the slaves' wages as their own. Like all of them. So slavery finds a way to survive in the South, but the biggest expense becomes security and finding ways to keep slaves from defecting.
So with business booming, gradually things get better in the North, to the point that union organizers and the government are actively reducing the work week from "every waking hour" to 60 or so hours a week. So leisure activities take hold in the North and trickle into the South. One little wrinkle - a Georgia man dies playing football, and the legislature passes a bill outlawing the sport in the state. The man's mother writes to the governor and asks him to veto the bill, saying how much her son loved the game. Unmoved by the love for a "damn Yankee game," the governor signs the bill, and other Southern legislatures follow suit until the Richmond government finally outlaws it and other "blood sports." (OTL the governor actually vetoed the bill.) As such, Southerners continue to play illegal sports, which become associated with alcohol and gambling, things the religious leaders speak against and state legislatures resoundingly outlaw.
The ban lasts until the Depression sets in, with Confederate president Richard Russell Jr. famously quipping, "I could go for a cold beer and a good clean game of football." Confederate state legislatures remain divided on alcohol and all but Louisiana prohibits gambling going forward, but the only state that continues the sport prohibition is the notoriously conservative Arkansas, a state that President Russell decries as "a theocracy." Meanwhile, relations between the Union and Confederacy begin to warm as the sides suffer through the Depression and begin to implement similar economic reforms. The two nations still fail to see eye-to-eye politically or socially, as most Southern blacks are still enslaved whereas most Northern blacks are treated equally under the law (money permitting, of course.) Also the North has a fully functional Labor party that has established itself as one of the two major parties against the Federal party, seen as the party of business; however, the South is ruled by a single party, the Democrats, and most seats in the Richmond government are uncontested.
Both nations grow in territory, as the Union grabs land in western Canada, Alaska, the Pacific, and parts of the Caribbean while the Confederacy dives into the Caribbean, Mexico and Central America. Gains from Spain probably go to the Union (it was an NY newspaper that ropes the US into war with Spain) while gains from Britain or France probably go to the Confederacy. The South dives into northern Mexico, eventually claiming a big chunk (excluding Baja California.) The Confederacy ends up in Central America as well, but the first big joint project between the two nations is the Panama Canal, which ends up somehow property of the USA, the CSA and Panama all at once until it's returned to Panama at a significantly later date than OTL.
So goon into WWII, the nations that were once bitter enemies have become friends, the slavery economic model is gradually phased out, and in need of manpower for the War, the South offers citizenship to blacks who enlist and take combat roles. (If nothing else, the South gets roped in by Hitler being an unclassifiably huge dipshit and declaring war on both the USA and CSA.)
So the Union regroups. It moves its capital, finally settling on the shores of Chicago after the Great Chicago Fire, essentially splitting the city into a federal district and the Illinois section. (My expected POD would be that the Baltimore Plot succeeds, Lincoln isn't there to prevent anything from Maryland joining the South to the British interfering, Hamlin fucks everything up, and D.C. ends up in Confederate hands.) The Union passes a few amendments to the Constitution, one called the Lincoln amendment that defines presidential succession and includes everything from protection of the President-elect to succession from Election Day to the day of leaving office, and furthermore it makes the President's term start on the same day as Congress' terms just to prevent a long period of the President-elect waiting around to be shot at before taking office. So the Lincoln amendment is number 13 and it's a handful.
Next up is an amendment banning secession, possibly putting in a really difficult escape clause. Next up slavery is outlawed, because Kentucky, Missouri and WV have slaves and the Union really fucking hates slavery. Next up is the equal protection amendment applying to the states, because this makes the former slaves citizens as kind of a "look at how much better we treat our blacks here, you dirty Southern assholes" measure - even if the Union is decidedly racist, it's hard to see blacks being looked at as that different from any other ethnic group after a while, given that there's about to be a fuckton of immigration anyway and ethnic strife is as old as humanity, let alone America, so the end of the stick black folks get is shitty but not as shitty as OTL and they share that burden with Irish folks, Jews, Asians, and maybe even Italians. Finally the Voting Rights amendment. And since it's about to become necessary, the income tax amendment.
The USA's saving grace is the Industrial Revolution. The already largely urban North will be rife with industry seekers and possibly even defectors from the South. Escaped slaves will seek out jobs in factories, and when industry reaches the South, all of a sudden slave owners are going to go bankrupt with these now useless human assets - unless they turn their plantations into "company towns" and take a cut of the slaves' wages as their own. Like all of them. So slavery finds a way to survive in the South, but the biggest expense becomes security and finding ways to keep slaves from defecting.
So with business booming, gradually things get better in the North, to the point that union organizers and the government are actively reducing the work week from "every waking hour" to 60 or so hours a week. So leisure activities take hold in the North and trickle into the South. One little wrinkle - a Georgia man dies playing football, and the legislature passes a bill outlawing the sport in the state. The man's mother writes to the governor and asks him to veto the bill, saying how much her son loved the game. Unmoved by the love for a "damn Yankee game," the governor signs the bill, and other Southern legislatures follow suit until the Richmond government finally outlaws it and other "blood sports." (OTL the governor actually vetoed the bill.) As such, Southerners continue to play illegal sports, which become associated with alcohol and gambling, things the religious leaders speak against and state legislatures resoundingly outlaw.
The ban lasts until the Depression sets in, with Confederate president Richard Russell Jr. famously quipping, "I could go for a cold beer and a good clean game of football." Confederate state legislatures remain divided on alcohol and all but Louisiana prohibits gambling going forward, but the only state that continues the sport prohibition is the notoriously conservative Arkansas, a state that President Russell decries as "a theocracy." Meanwhile, relations between the Union and Confederacy begin to warm as the sides suffer through the Depression and begin to implement similar economic reforms. The two nations still fail to see eye-to-eye politically or socially, as most Southern blacks are still enslaved whereas most Northern blacks are treated equally under the law (money permitting, of course.) Also the North has a fully functional Labor party that has established itself as one of the two major parties against the Federal party, seen as the party of business; however, the South is ruled by a single party, the Democrats, and most seats in the Richmond government are uncontested.
Both nations grow in territory, as the Union grabs land in western Canada, Alaska, the Pacific, and parts of the Caribbean while the Confederacy dives into the Caribbean, Mexico and Central America. Gains from Spain probably go to the Union (it was an NY newspaper that ropes the US into war with Spain) while gains from Britain or France probably go to the Confederacy. The South dives into northern Mexico, eventually claiming a big chunk (excluding Baja California.) The Confederacy ends up in Central America as well, but the first big joint project between the two nations is the Panama Canal, which ends up somehow property of the USA, the CSA and Panama all at once until it's returned to Panama at a significantly later date than OTL.
So goon into WWII, the nations that were once bitter enemies have become friends, the slavery economic model is gradually phased out, and in need of manpower for the War, the South offers citizenship to blacks who enlist and take combat roles. (If nothing else, the South gets roped in by Hitler being an unclassifiably huge dipshit and declaring war on both the USA and CSA.)