The Lincoln-Douglas debates were a series of seven debates 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 on important issues of the time, particularly the expansion of slavery into new territories. Lincoln argued against the spread of slavery, while Douglas supported popular sovereignty, allowing states to decide for themselves. These debates were significant not only for their content but also for their impact on American politics. They helped to elevate Lincoln's national profile, setting the stage for his successful campaign for the presidency in 1860. The debates highlighted the deep divisions in the country leading up to the Civil War.