[absolootezer0]

Why did the South use slaves, then, rather than simply trying to attract immigrant laborers (who would seem, economically, to offer a better deal)?

that's always been my proof that if licoln had any sense of economics whatsoever, we'd have had no civil war.
slavery was already on the road down. slave importation had already been stopped, so the only source of new slaves were those being born. it wouldn't have been very long before plantation owners would have realised that slaves were no longer worth their trouble.
if licoln had offered (but not forced) to buy all the slaves, at fair market value, war would've been avoided, and even all that expense of buying all the slaves would have been cheaper than paying for the war.

[Non-Sequitur]

slavery was already on the road down. slave importation had already been stopped, so the only source of new slaves were those being born. it wouldn't have been very long before plantation owners would have realised that slaves were no longer worth their trouble.

Based on census data available the slave population was growing at healty clip, as fast as the white population in the South. Demand for slaves was high, prices were high, and there was no substitute for slave labor available. Doesn't sound like slaves were trouble for their owners to me. More like the pillar of Southern society and wealth.

if licoln had offered (but not forced) to buy all the slaves, at fair market value, war would've been avoided, and even all that expense of buying all the slaves would have been cheaper than paying for the war.

Such offers were make by Lincoln during the rebellion, and were ignored by the South. if licoln had offered (but not forced) to buy all the slaves, at fair market value, war would've been avoided, and even all that expense of buying all the slaves would have been cheaper than paying for the war.