The Beaux Arts style Lee County Courthouse was constructed in 1901 following the designs of Chicago-based architect C.E. Brush, best known for designing the first buildings on the Northern Illinois University campus. The courthouse replaced an earlier 1840 courthouse, which stood on the site. The land was donated as a public square by founding settler, John Dixon. Also on the property is a large stone with a plaque that marks the location where Abraham Lincoln gave a speech in 1856. Two years earlier, he was elected to the State Legislature but resigned to run for the United States Senate, a race he ultimately lost. Because of this, he changed his party from Whig to Republican. As part of his Dixon speech, Lincoln made a plea for the support of presidential candidate John C. Frémont, who ultimately lost to James Buchanan. President Buchanan served for one term and was followed by President Abraham Lincoln in 1861.