The Lincoln-Douglas debates were a series of seven debates held in 1858 between Abraham Lincoln and Stephen A. Douglas, who were competing for a seat in the U.S. Senate from Illinois. These debates focused primarily on the issue of slavery and its expansion into new territories. Lincoln argued against the spread of slavery, while Douglas supported popular sovereignty, allowing territories to decide for themselves. The debates gained national attention and showcased the contrasting views of the two candidates. Although Douglas won the election, the debates helped elevate Lincoln's profile, setting the stage for his future presidential campaign and the national conversation on slavery.