Now, what was Douglas' position? Douglas was the man who in 1854, in drafting and sponsoring the Kansas-Nebraska Act, had moved for the repeal of the Missouri Compromise restriction on slavery. And that meant that after Missouri was admitted to the Union in 1820 or '21, that Congress resolved that in all the remaining territory north of 36&Mac251;30'—which was a southern boundary of Missouri—all the remaining territory would be forever free. That meant that the states of Kansas, Nebraska, North Dakota, South Dakota, and parts of Colorado and Wyoming—slavery was excluded from them.

The Real Abraham Lincoln: A Debate (2002)