In June 1858, the Illinois Republican Convention nominated Lincoln to challenge Douglas for the U.S. Senate. Lincoln invited Douglas to a series of debates on July 24, setting the stage for what would become one of the most famous local political contests in U.S. history and a precursor to the 1860 presidential election. Prior to the seven debates between Lincoln and Douglas, Lincoln had already made sixty-three speeches in 1858, and Douglas claimed to have made 130. Douglas, the incumbent, was more widely known than Lincoln and had the numeric advantage of the Democrats in the Illinois General Assembly, which selected U.S. senators in those days. He also represented a divided party and faced a growing population in northern Illinois that was hostile to slavery. Lincoln, on the other hand, had the advantage of a united Republican Party, a growing antipathy toward slavery in the state, and a reputation for integrity. Nevertheless, his views on racial issues were unpopular, as was his stand on the Mexican War. The debates would highlight the fundamental differences in the men’s characters and focus on the main issues of the day, the expansion of slavery and racial equality. While the immediate effect of the debates was the re-election of Douglas, the long-term results were the opposite. Lincoln was catapulted to national prominence, allowing him to run for president in 1860, and Douglas’s campaign against Lincoln diminished his chances of future success. See 1858 Federal Election; 1860 Republican National Convention.

The seven debates each appeared in contemporary newspapers, from which Lincoln compiled a scrapbook that served as the source for the first publication of all of the debates in 1860.