America without the Civil War

[True Federalist (진정한 연방 주의자)]

This is going to require a South that is far less cocky in 1860 to have a shred of a chance of happening.  The most obvious way for that to happen is for there to be a less severe Panic of 1857.  Ways for that to happen would include the bill to reestablish the Second Bank of the United States not being vetoed by Tyler in 1841 and/or the SS Central America doesn't sink (with a lot of specie aboard).

With a North that was more obviously stronger economically and a less cocky South, there might not have been secession resulting from Lincoln's election.  With Southerners remaining in Congress, it is doubtful that much, if any, of the Republican platform would pass into law during the 37th Congress, since the Democrats would have retained control of the Senate.

No chance that slavery is abolished in only a decade.  Absent secession, likely Texas splits into multiple States in an attempt to keep the sectional balance going and the Corwin Amendment is ratified.  (Especially if South Carolina secedes but fails to get other States to leave with it and the Corwin Amendment is used to lure it back in.)  Indeed, slavery likely lasts into the 20th Century without a Civil War.

If there is a Spanish-American War, it happens sooner so as to add Cuba as a slave State.

[True Federalist (진정한 연방 주의자)]

Indeed, slavery likely lasts into the 20th Century without a Civil War.

That's an even bigger stretch than my own interpretation, particularly with the advent of the industrial revolution.

Not really.  Take for example cotton. Mechanical cotton pickers didn't become commercially viable in this country until the labor shortages of World War II led to their adoption.  In some third world countries, cotton cultivation is still done by hand rather than using expensive machinery.  With cheap and abundant slave labor, there is little economic incentive to mechanize most agricultural production.  While slave labor is inefficient if one includes the slaves in computing per capita GDP, exclude them and you can get the same or higher results for the elites that remain.

Imagine if you will a county in which jobs now done by illegal immigrants are instead done by slave labor.  While morally repugnant, economically it is roughly equivalent and maybe even more advantageous to those who currently hire illegals.  The case against slavery is not based on economics, but on morality.

[True Federalist (진정한 연방 주의자)]

The civil war would have taken place. It was the divide over so many tarrifs and taxes, it wasnt about slavery.

As I pointed out earlier, if the southern States had not seceded, the Republicans would never have been able to enact their economic platform into law as the Democrats would have had solid control of the Senate. The tariff couldn't have gone up in 1861 without secession.

However, there is a small kernel of truth to what you say.  Were it not for the economics of plantation slavery, the South would not have been as opposed to tariffs as it was.  The economic system the South preferred had the South specializing in slave labor production of agricultural commodities (as agriculture was and still is the economic area in which slave labor suffers the least disadvantage in comparison with free labor).  High tariffs were disadvantageous to an economy dependent upon the use of slave labor to produce agricultural commodities for export.  Southern opposition to tariffs was because they correctly saw them as negatively impacting slavery, not because of any high-minded devotion to free trade.