On the day after the Quincy debate, both Lincoln and Douglas got aboard the City of Louisiana and sailed down the Mississippi River to Alton, for the final encounter of the campaign. Looking haggard with fatigue, Douglas opened the debate on October 15 in a voice so hoarse that in the early part of his speech he could scarcely be heard. After briefly reviewing the standard arguments over which he and Lincoln had differed since the beginning of the campaign, he made the peculiar decision to devote most of his speech to a detailed defense of his course on Lecompton.

Six days after Galesburg, the candidates met again at Quincy, a town in west-central Illinois that at one time had been Douglas’s home district. Adams County was regarded as “Democratic, though not overwhelmingly so.” Located in the disputed central Illinois area, it was a crucial battleground for both sides, and both saw reasonable prospects of victory. There was not much evolution of arguments between Galesburg and Quincy, although Lincoln was more explicit in his delineation of the moral issue.

The fifth debate took place in Galesburg, three weeks after the Charleston meeting. In the mid-1850s, Galesburg was a central hub of Illinois abolitionism. Settled by immigrants between 1840 and the early 1850s, it was a solid bastion of Republicanism. It also produced the highest attendance, between fifteen and twenty thousand. Douglas opened the debate, and, although he brought up Lincoln’s Charleston proclamations against racial equality as a way to embarrass his challenger, he and Lincoln both addressed issues of principle rather than personality.

Thus the three sections of Lincoln’s house divided speech had the inevitability of a syllogism: The tendency to nationalize slavery had to be defeated. Stephen A. Douglas powerfully contributed to that tendency. Therefore, Stephen A. Douglas had to be defeated. Attracting national attention, Lincoln’s house-divided speech sounded very radical. Advanced five months before William H. Seward offered his prediction of an “irrepressible conflict” between slavery and freedom, it was the most extreme statement made by any responsible leader of the Republican party.

Both Lincoln and Douglas knew that the election of 1858 would be decided by swing voters in central Illinois counties where only three of the seven debates were held. The debates were, yes, a central feature of the campaigns of 1858, but in the narratives, they have come completely to eclipse the campaigners. That is, in large measure, the accident of print.