Question

what did Lincoln mean when he said: "A house divided against itself cannot endure, permanently half slave and half free. I do not expect the Union to be dissolved--I do not expect the house to fall--but I do expect it will cease to be divided. It will become all one thing, or all the other."

Answer 1

"A house divided" means that a group of people suddenly turn against each other instead of working together and try to argue their way through, and Lincoln sees this as not a wise option.