Answer:
Abraham Lincoln gave his "House Divided" speech on June 17, 1858, when he was running for senator in Illinois. He lost the election to the incumbent Stephen Douglas, but beat Douglas and two others to be elected President in 1860.
Where the Declaration of Independence stressed the right of a people to sovereignty, Lincoln was saying that the Southern states wanted their own laws that conflicted with those of the other states of the Union, to which they had freely joined. He said that the US must either have slavery legal everywhere, or illegal everywhere.
The courts at the time had been confusingly inconsistent on the right of one person to enslave another, as occurred in the South. But Northern abolitionists were pressing to end slavery completely, to the detriment of the agriculturally-dependent South.
