As for slavery, it was already on it's way out at the time of the civil war. Advancements in machinery were already making slave holding too expensive a proposition.
I’ve heard this claim a million times, yet despite the supposedly receding tide of slavery, the South was fighting tooth and nail to expand slavery into new territories.
Slavery being an increasingly losing financial proposition was, of course, why slave prices reached an all-time high in 1860. People are always interested in investing their money in known declining industries.
Slavery may have been on its way out, as an economic proposition - but the fact is, it needed killing as a moral proposition.
It would not do to simply let it die an economic death, but retain in our national conscience the notion that it was morally acceptable.
If it was on the way out then what was Kansas all about?
Total nonsense. In 1860, slavery had never been more profitable and would have continued to remain profitable for many more generations had it continued. Cotton was still picked by hand all the way into the 1950s. And even today, we still have migrant 'stoop labor' working on farms.
Slavery was not on its way out. Rather, the first fruits of the industrial revolution created increased demand for its products. Slavers were desperate for new unspoiled land, hence their revolt against the Republican party that was pledged to (1) let slavery die where it was and (2) deny slavers the opportunity to poison any new states or territories, as had been done by the founders with the Northwest Ordinance.