In which speech did Lincoln say 'A house divided against itself cannot stand'?

Lincoln said “A house divided against itself cannot stand” in his House Divided speech. He delivered it on June 16, 1858, in Springfield, Illinois, after accepting the Republican Party’s nomination for the U.S. Senate.

The speech addressed the growing crisis over slavery. Lincoln argued that the United States could not remain permanently divided between slave states and free states. He was warning that the conflict would eventually force the nation toward one condition or the other, rather than predicting that the Union would immediately dissolve.

The phrase came from the Bible, including Mark 3:25, but Lincoln applied it to American politics. It is often confused with the Gettysburg Address or the Second Inaugural Address because all three are among his best-known speeches. The Cooper Union speech, delivered in 1860, helped his presidential campaign but did not contain this famous line.