Old Main is the oldest building on the Knox College campus and one of the most historically significant structures in Illinois. A simple but dignified building in the Collegiate Gothic style, completed in 1857, it achieved its place in American history the following year when Lincoln and Douglas debated on its steps. The building is a National Historic Landmark and can be visited as part of a walk through the Knox campus.
Knox College was founded by Presbyterian ministers with a strong anti-slavery stance, which made Galesburg a natural venue for one of the most consequential debates in American political history. Lincoln found a friendly crowd here; the Galesburg audience was largely abolitionist. The debate addressed the Kansas-Nebraska Act and the expansion of slavery into the territories — questions that would, within three years, lead to civil war.