Galesburg, the fifth of the Lincoln-Douglas debates of 1858, marked a strategic turning point in the series, when the momentum of the debates shifted from Stephen A. Douglas to Abraham Lincoln. Lincoln established a lead on the argument about the hypothetical Dred Scott II future Supreme Court decision, the moral argument about slavery, the argument about the 1854 Republican platform, and in the use of refutation strategies. He would build upon these gains in the remaining debates, while Douglas’s position would remain constant. The essay illustrates how critics can examine the rhetorical dynamics of a political debate. This essay was originally presented at the Knox College celebration of the centennial of the Galesburg debate in October, 2008. It is reprinted from Argumentation and Advocacy, 46 (Summer 2010), 140–149.