There was a series of seven debates between the Democrat senator Stephen A Douglas and Republican Abraham Lincoln held August-October during the 1858 race for Illinois State senator. The main agenda for the debates was the topic of slavery which was the hot button for the nation at that time. Lincoln was against the further expansion of slavery, believing it immoral, but held that it should not be banned in existing slave states; Douglas advocated each state’s right to choose whether to be a slave or free state.
The issues of states’ rights and the expansion of slavery brought about a question of how a territory could in fact have popular sovereignty in view of the Dred Scott Decision, which effectively made slavery legal in all territories? Douglas’s reply, that a territory could be a free territory by not establishing local slave’s codes, enraged his southern proslavery supporters and became known as the Freeport Doctrine. Lincoln accepted the Republican nomination to run for Senate and he challenged the incumbent Douglas to a series of debates. Each of the debates lasted three hours; the first candidate stated his case in the initial hour, the second spoke for an hour and a half, and the first speaker would reply in the last half hour of the debate. Spectators numbered from 6,000 to 15,000 on each occasion. Although Douglas won the election and served as senator of Illinois that term, the Freeport Doctrine eventually led to the split of the Democratic Party and his loss of the future presidential campaign to Lincoln, who had gained national recognition from the debates.
The question of the extension of slavery into the territories acquired from Mexico dominated the seven debates. The most notable exchange occurred at Freeport on August 27, 1858. There Lincoln attempted to exploit the weakness of the popular sovereignty doctrine which had been imposed by the Dred Scott decision and, in the process, put Douglas on the spot.