The Missouri Compromise has kept the peace between North and South for thirty-four years. It is revered by most Americans. Now it seems clear that Southern slaveowners want to make the whole nation accept slavery. They want to throw out the compromise. The abolitionists are appalled. A torrent of fiery speeches and sermons denounce the Kansas-Nebraska Act. Many Northerners who haven't really liked the abolitionists—because they seem like extremists—now join their ranks. An Illinois lawyer, whose name is Abraham Lincoln, is chosen in 1858 by the newly formed Republican party to run against Douglas for the U.S. Senate. He says that slavery is more than a moral problem—the very nation is in danger. And then he delivers these remarkable words : "A house divided against itself cannot stand. I believe this government cannot endure, permanently half slave and half free.... It will become all one thing, or all the other."

Abraham Lincoln is different from most of those who oppose slavery. He is without malice. He doesn't hate the slave owners. Human nature being what it is, he says, southern whites are doing what northern whites would do if they were in their place. That, however, doesn't excuse slavery. He thinks it wrong and says so: "Let us have faith that right makes might, and in that faith let us, to the end, dare to do our duty as we understand it."

Stephen Douglas is an important man. People pay attention when he speaks. It is a big piece of luck for Lincoln. Because he is Douglas's opponent, he can't be ignored. Lincoln and Douglas climb on a train and debate at train stops across Illinois . Douglas talks of popular sovereignty, the right of people to govern themselves. Lincoln goes to the heart of the matter. He says , "We began by declaring that 'all men are created equal'; but now we have run down to the other declaration, that for some men to enslave others is a 'sacred right of government.' These principles cannot stand together ."