What self-interested incentives did white Northerners have to oppose slavery?

So, not in the middle?

I agree that too many people define themselves as middle class but the upper quintile (minus those who are 2 standard deviations) seems overly restrictive.

Middle class isn’t about income percentiles, IMO, and there very well may have been a time in US history when a larger percentage was middle class than now (although I don’t think any serious academic thinks it was ever as high as 70%) but the 1870s was so not that time.

When I say “middle class”, I mean professionals, managers, and senior civil servants, as well as the petite bourgeoisie

It’s not about quintiles, it’s about them being in the middle of a 3-tier system, wherever that is.

I completely agree that the nascent middle classes amounted to no more than maybe 20% of the population in large cities around 1870. It would have been a smaller number in small towns.

I also completely agree that virtually all of these middle class households would have at least one servant. Many would have a cook and a maid. Having a servant was the status symbol of being middle class; not having one would be literally déclassé.

The vast majority of northern households with servants used ethnics, often immigrants. Good cooks were more prized in those days with fickle wood stoves so they may have been older residents but the basic scrubbing maid was about as low a job as a white woman could take.

Middle class homes with servants would stay a thing until WWII, but declined rapidly after about 1900. The “servant problem” was a constant in articles aimed at the middle class starting around then because the huge increase in factories offered woman better paying jobs with fewer hours and the ability to live at home. For all their horrors, factory work was seen as a step up from being a servant.

That opened jobs for black women. The Great Migration northward that began around 1910 boosted the black population of northern cities by the hundreds of thousands. In 1870 Chicago, probably no more than 1% of the population was black. From 1916-1919 alone more than 50,000 blacks landed there. Those classic Hollywood movies and 50s tv shows with their plethora of black maids represented the reality that white servants were increasingly more difficult to find.

Upper class homes had zillions of servants, of course, but then as now the 1% is the 1% and not representative of American life.

I believe the issue here is a matter of terminology: The “Middle” class was defined originally by being between the laboring classes and the (supposedly) independently wealthy. as originally intended, it meant between the peasantry and nobility. A more comparable group update would be what is referred to as the “Upper Middle” class, or even the bourgoise. These groups not uncommonly have domestic servants today in some fashion.

I was reading how slavery ended in ancient Rome, and I wonder if anti-slavers had this same notion (other than the listed reasons): It was just more economical. You can walk a horse to a blacksmith in Rome for a small fee to get it horseshoed rather than having to maintain/clothe/shelter/train a slave to do the same thing.
I’m wondering why the South didn’t realize this.

Yes, we all wonder why the South spent 250 years embracing an economic system based on slavery without ever once questioning the effectiveness of it. Or why a culture that worshiped Rome and the way that their entire economic system ran on slavery never gave a thought to emulating them by ending slavery. Or who the scholars are that thought that Rome actually ended slavery, since they seem to be unknown to the academics who believe that slavery outlived the western Roman empire. Yes, a whole lot of wondering goin’ on.

I’m not sure where Rome comes into this, because Exapno is correct that Rome never actually outlawed it, although it was clearly fading into unimportance by the 4th century.

However, slavery in the South held on because it was profitable enough for those who owned them, and they had the money and time to dominate politics & so on. Nothing more.

I think those lynchings were more the result of the church burnings than the Wide Awake demonstrations.

This is incorrect for the reasons pointed out, but people did this type of thing anyways. Unless you had a big operation and needed someone to shoe horses full time, you didn’t train a slave to shoe horses, you hired someone. I mean, my family needs haircuts, but I don’t keep a barber on staff.