How. By winning an election? South Carolina followed by the other cotton states threatened to secede numerous times from 1830 onward, long before anyone outside of Springfield every heard the name Abraham Lincoln.
There was nothing Lincoln did that "caused" the situation." That situation had existed since 1820 and in fact even before back to the 3/5 compromise of 1787. As Jefferson said at that time, it would eventually explode, and Lincoln just happened to be the guy in the hot seat when it happened and thank God he was or this nation would have ended and along with it, the last best hope of freedom.
"the last best hope of freedom."
That went with the surrender of the Confederacy.
Lincoln didn't have the gumption to stand up and stop the rape of the southern commerce and didn't have the good sense to allow them to deal with slavery on their own terms.