The famous Lincoln-Douglas debates were held in what year and for what public office?

The Lincoln–Douglas Debates of 1858 (also known as The Great Debates of 1858) were a series of seven debates between Abraham Lincoln, the Republican candidate for the United States Senate from Illinois, and incumbent US Senator Stephen Douglas, the Democratic Party candidate.

At the time, US Senators were elected by state legislatures; thus Lincoln and Douglas were trying for their respective parties to win control of the Illinois legislature. Although Illinois was a free state, the main issue of the debates was the question of slavery in the US. On election day, the Democrats won 40 seats in the state house of Representatives, and the Republicans won 35. In the state senate, Republicans held 11 seats, and Democrats held 14. Stephen A. Douglas was reelected as US Senator of Illinois by the legislature, 54-46, even though Abraham Lincoln won the popular vote with a percentage of 50.6%, or by 3,402 votes. However, the widespread media coverage of the debates greatly raised Lincoln's national profile, making him a viable candidate for nomination as the Republican candidate in the upcoming 1860 presidential election. Lincoln would win the 1860 election and become the 16th President of the US.