Lincoln was elected with a majority of the electoral votes, 180 out of 303. He only received 40% of the votes but that was more than every other candidate.
The Confederacy
The South threatened to leave the union and did, and they held a special convention and voted to secede
Reactions to Secession
John Crittenden made a compromise that they would protect slavery south of 36 30'N latitude. But no one was on board.
Presidential Responses
You aren't allowed to leave the union.
Since South Carolina left the Union, other states wanted to join South Carolina. Which is what Texas, Lousiana, Mississippi, Alabama, Florida, and Georgia did.
I'm leaving!
We are joining you
Most southerners welcomed secession and they rang bells and fired cannons and celebrated.
Fire!
James Buchanan sent a message to congress saying that the southern states couldn't leave the union. Since Lincoln wasn't president he couldn't do anything about it yet.