WI the South USA does not secede when it did IOTL?

Suppose USA South does not secede in 1860-1? I think there was every
reason to hope for a Democratic return to power before slavery was
sevwerely damaged. I can't get over how easy both sides, especially
the CSA thoght victory would be. What were they smoking.

I think however if the Civil War was inevitable the longer it could be
delayed the easier the Union victory would be. OTOH if the war had
come about 10 years earlier the South might have at least made
defeating it harder. I have a feeling the advance of technology helps
the centralized power in such a deal.

Who knows how the Reveloutionary War might have gone with ****pping
advanced another 50 or 100 years.