The Missouri Compromise allowed Missouri to be allowed into the Union as a slave state in 1820; however, no further slave states were to be allowed above the southern border of Missouri after this Compromise. In Chapter 9 of To Kill a Mockingbird, Scout relates that her Cousin Ike Finch, the last surviving Confederate veteran, was visited by her family at least once a year; at that time he would allude to this Compromise when speaking to Atticus,
"Tell you, Atticus...the Missouri Compromise was what licked us, but if I had to go through it agin I'd walk every step of the way there an' every step back jist like I did before an' furthermore we'd whip 'em this time.
With a limited number of slave states, the Confederacy simply was outnumbered in the war: Union soldiers numbered over two million while the Confederate soldiers were only slightly more than one million. With the Missouri Compromise, then, the Confederacy was limited in its numbers and, consequently, its projects and victories.