Because Slavery is completley okay and state's rights beat human rights...
You really should open a history book if you think
A.) Lincoln cared even a tad about freeing the slaves (the I'd free all the slaves or none of the slaves to free the union quote)
B.) The Civil War was based on slavery
No he did not but he was against it expanding in any form and the Republican Party was the more leftist party against freeing the slaves. Lesser of two evils here.
Also on the bottom one wtf? The Civil War was almost totally based off of slavery, and the issues it created. The deep South seceeded from the Union because it was afraid Lincoln would free all the slaves and destroy their economy, and most of the upper South seceeded because Lincoln was going to put down the rebellion and march on the Confederacy. This was unacceptable to most of the Upper South.
The lower south seceded over tariffs and state right's, the upper South seceded because they did not want Lincoln to start a war
This is what caused South Carolina to seceede and they say it themselves:
The refusal of Northern states to enforce the fugitive slave code, violating Southern personal property rights;
Agitation against slavery, which "denied the rights of property".
Assisting "thousands of slaves to leave their homes" through the Underground Railroad.
The election of Lincoln "because he has declared that 'Government cannot endure permanently half slave, half free,' and that the public mind must rest in the belief that slavery is in the course of ultimate extinction
"...elevating to citizenship, persons who, by the supreme law of the land, are incapable of becoming citizens". Most Northerners opposed the Dred Scott decision, although only a few New England states allowed blacks an equal right to vote.
That is in their own words. Now if you really think the whole Civil War was started because of some tarriffs you must be smoking something. It was a factor that did make some rich planation owners pretty pissed but it is almost all slavery.