I firmly believe Slavery would have been abolished naturally had the north stopped bullying the south for it. Heavy Tariffs on imports the south used that didn't even get reinvested into the south wasn't a good thing. Automation in farming could have come sooner with that money the north was taking from the southerners and with the automation, it would have been more economical to just have the machines than it was slave labor.
Edit: women could vote prior to universal women's suffrage if they were land owners and many women at the time didn't want it either because they understood it as also having to apply for selective service. Meanwhile many men who were selected for the draft had no say in the politicians that sent them off to war because they were unable to vote.