After his defeat by Lyman Trumbull in the 1856 Senate election, Abraham Lincoln began planning to run against Douglas in the 1858 Senate election.
Lincoln strongly rejected proposals to cooperate with Douglas against Buchanan, and he won the Republican nomination to oppose Douglas.
Accepting the nomination, Lincoln delivered his House Divided Speech, saying "A house divided against itself cannot stand.
I believe this government cannot endure, permanently half slave and half free.
I do not expect the Union to be dissolved–I do not expect the House to fall–but I do expect it will cease to be divided.
It will become all one thing, or all the other."
Douglas rejected Lincoln's notion that the United States could not continue to be divided into free states and slave states, and warned that Lincoln called for "a war of secession, a war of the North against the South, of the free states against the slave states."

Lincoln and his entourage began following Douglas around the state, campaigning in the senator's wake.
Eventually, Douglas agreed to debate Lincoln in seven different venues across the state.
The format of the Lincoln-Douglas Debates called for one candidate to make a one-hour opening speech, followed by the other candidate delivering a ninety-minute rebuttal, followed by the first candidate delivering a half hour closing remark; Lincoln and Douglas agreed to rotate who would speak in the two slots.
The debates focused on the issue of slavery in the territories, and, more broadly, the meaning of republicanism in the United States.
Douglas favored popular sovereignty and emphasized the concept of self-government, though his vision of self-government only encompassed whites.
Lincoln, meanwhile, emphasized human equality and economic opportunity for all.

In the second debate, Douglas articulated the Freeport Doctrine, holding that the people in federal territories had "the lawful means to introduce [slavery] or exclude it as they please, for the reason that slavery cannot exist a day or an hour anywhere, unless it is supported by local police regulations.
Those police regulations can only be established by the local legislature; and if the people are opposed to slavery, they will elect representatives to that body who will by unfriendly legislation effectually prevent the introduction of it into their midst."
Thus, Douglas argued that territories could effectively exclude slavery despite the Dred Scott decision.
At another appearance, Douglas reiterated his belief that the Declaration of Independence was not meant to apply to non-whites.
He said, "this government was made by our fathers on the white basis ... made by white men for the benefit of white men and their posterity forever".

For his part, Lincoln criticized Douglas for his moral indifference to slavery, but denied any intention of interference with slavery in the South.
He suggested that, despite the public break between Douglas and Buchanan over Kansas, the two Democrats had worked together to extend and perpetuate slavery.
Lincoln disclaimed the radical-for-the-time views on racial equality attributed to him by Douglas, arguing only for the right of African Americans to personal liberty and to earn their own livings.
He stated, "I am not, nor ever have been in favor of making voters of the negroes, or jurors, or qualifying them to hold office, or having them to marry with white people."
At another debate, Lincoln stated, "I believe that slavery is wrong... There is the difference between Judge Douglas and his friends and the Republican Party."

Following the final debate, Illinois voters headed to the polls for Election Day.
In an election that saw higher turnout than that of the 1856 presidential election, Democrats won 54 of the 100 seats in the state legislature.
Despite the split with Buchanan and the strong challenge from Lincoln, the state legislature elected Senator Douglas to a third term in January 1859.
Following the elections, Douglas toured the South.
He warned against sectionalism and secession, telling one crowd, "if you deem it treason for abolit
After his defeat by Lyman Trumbull in the 1856 Senate election, Abraham Lincoln began planning to run against Douglas in the 1858 Senate election. Lincoln strongly rejected proposals to cooperate with Douglas against Buchanan, and he won the Republican nomination to oppose Douglas. Accepting the nomination, Lincoln delivered his House Divided Speech, saying "A house divided against itself cannot stand. I believe this government cannot endure, permanently half slave and half free. I do not expect the Union to be dissolved–I do not expect the House to fall–but I do expect it will cease to be divided. It will become all one thing, or all the other." Douglas rejected Lincoln's notion that the United States could not continue to be divided into free states and slave states, and warned that Lincoln called for "a war of secession, a war of the North against the South, of the free states against the slave states."
Lincoln and his entourage began following Douglas around the state, campaigning in the senator's wake. Eventually, Douglas agreed to debate Lincoln in seven different venues across the state. The format of the Lincoln-Douglas Debates called for one candidate to make a one-hour opening speech, followed by the other candidate delivering a ninety-minute rebuttal, followed by the first candidate delivering a half hour closing remark; Lincoln and Douglas agreed to rotate who would speak in the two slots. The debates focused on the issue of slavery in the territories, and, more broadly, the meaning of republicanism in the United States. Douglas favored popular sovereignty and emphasized the concept of self-government, though his vision of self-government only encompassed whites. Lincoln, meanwhile, emphasized human equality and economic opportunity for all.
In the second debate, Douglas articulated the Freeport Doctrine, holding that the people in federal territories had "the lawful means to introduce [slavery] or exclude it as they please, for the reason that slavery cannot exist a day or an hour anywhere, unless it is supported by local police regulations. Those police regulations can only be established by the local legislature; and if the people are opposed to slavery, they will elect representatives to that body who will by unfriendly legislation effectually prevent the introduction of it into their midst." Thus, Douglas argued that territories could effectively exclude slavery despite the Dred Scott decision. At another appearance, Douglas reiterated his belief that the Declaration of Independence was not meant to apply to non-whites. He said, "this government was made by our fathers on the white basis ... made by white men for the benefit of white men and their posterity forever".
For his part, Lincoln criticized Douglas for his moral indifference to slavery, but denied any intention of interference with slavery in the South. He suggested that, despite the public break between Douglas and Buchanan over Kansas, the two Democrats had worked together to extend and perpetuate slavery. Lincoln disclaimed the radical-for-the-time views on racial equality attributed to him by Douglas, arguing only for the right of African Americans to personal liberty and to earn their own livings. He stated, "I am not, nor ever have been in favor of making voters of the negroes, or jurors, or qualifying them to hold office, or having them to marry with white people." At another debate, Lincoln stated, "I believe that slavery is wrong... There is the difference between Judge Douglas and his friends and the Republican Party."
Following the final debate, Illinois voters headed to the polls for Election Day. In an election that saw higher turnout than that of the 1856 presidential election, Democrats won 54 of the 100 seats in the state legislature. Despite the split with Buchanan and the strong challenge from Lincoln, the state legislature elected Senator Douglas to a third term in January 1859. Following the elections, Douglas toured the South. He warned against sectionalism and secession, telling one crowd, "if you deem it treason for abolit
Stephen A. Douglas