Stephen A. Douglas in the context of "1860 United States presidential election"

The Kansas–Nebraska Act of 1854 (10 Stat. 277) was a territorial organic act that created the territories of Kansas and Nebraska. It was drafted by Democratic Senator Stephen A. Douglas, passed by the 33rd United States Congress, and signed into law by President Franklin Pierce. Douglas introduced the bill intending to open up new lands to develop and facilitate the construction of a transcontinental railroad. However, the Kansas–Nebraska Act effectively repealed the Missouri Compromise of 1820, stoking national tensions over slavery and contributing to a series of armed conflicts known as "Bleeding Kansas".

The United States had acquired vast amounts of land in the 1803 Louisiana Purchase, and since the 1840s, Douglas had sought to establish a territorial government in a portion of the Louisiana Purchase that was still unorganized. Douglas's efforts were stymied by Senator David Rice Atchison of Missouri and other Southern leaders who refused to allow the creation of territories that banned slavery; slavery would have been banned because the Missouri Compromise outlawed slavery in the territory north of latitude 36° 30′ north (except for Missouri). To win the support of Southerners like Atchison, Pierce and Douglas agreed to back the repeal of the Missouri Compromise, with the status of slavery instead decided based on "popular sovereignty". Under popular sovereignty, the citizens of each territory, rather than Congress, would determine whether slavery would be allowed.

Abraham Lincoln (February 12, 1809 – April 15, 1865) was the 16th president of the United States, serving from 1861 until his assassination in 1865. He led the United States through the American Civil War, defeating the Confederate States and playing a major role in the abolition of slavery.

Lincoln was born into poverty in Kentucky and raised on the frontier. He was self-educated and became a lawyer, Illinois state legislator, and U.S. representative. Angered by the Kansas–Nebraska Act of 1854, which opened the territories to slavery, he became a leader of the new Republican Party. He reached a national audience in the 1858 Senate campaign debates against Stephen A. Douglas. Lincoln won the 1860 presidential election, prompting a majority of slave states to begin to secede and form the Confederate States. A month after Lincoln assumed the presidency, Confederate forces attacked Fort Sumter, starting the Civil War.

The Compromise of 1850 was a package of five separate bills passed by the United States Congress in September 1850 that temporarily defused tensions between slave and free states during the years leading up to the American Civil War. Designed by Whig senator Henry Clay and Democratic senator Stephen A. Douglas, with the support of President Millard Fillmore, the compromise centered on how to handle slavery in recently acquired territories from the Mexican–American War (1846–48).

The provisions of the compromise included a provision that approved California's request to enter the Union as a free state, and strengthened fugitive slave laws with the Fugitive Slave Act of 1850. The compromise also banned the slave trade in Washington, D.C. (while still allowing slavery itself there), defined northern and western borders for Texas while establishing a territorial government for the Territory of New Mexico, with no restrictions on whether any future state from this territory would be a free or slave state and established a territorial government for the Territory of Utah also with no restrictions on if the territory would become a slave or free state.

The Northern Democratic Party was a leg of the Democratic Party during the 1860 presidential election, when the party split in two factions because of disagreements over slavery. They held two conventions before the election, in Charleston and Baltimore, where they established their platform. Democratic Candidate Stephen A. Douglas was the nominee and lost to Republican Candidate Abraham Lincoln, whose victory prompted the secession of 12 Southern states and the formation of the Confederate States of America.

The Lincoln–Douglas debates were a series of seven debates in 1858 between Abraham Lincoln, the Republican Party candidate for the United States Senate from Illinois, and incumbent Senator Stephen Douglas, the Democratic Party candidate. Until the Seventeenth Amendment to the United States Constitution, which provides that senators shall be elected by the people of their states, was ratified in 1913, senators were elected by their respective state legislatures. Therefore, Lincoln and Douglas were trying to win the people's votes for legislators in the Illinois General Assembly, aligned with their respective political parties.

The debates were designed to generate publicity—some of the first examples of what in modern parlance would be characterized as "media events". For Lincoln, they were an opportunity to raise both his state and national profile and that of the burgeoning Republican Party, newly organized four years before in Ripon, Wisconsin, in 1854. For Senator Douglas, they were an opportunity to defend his record—especially his role in promoting the doctrine of popular sovereignty in regard to the issue of American black slavery and its role in the passage of the Kansas–Nebraska Act of 1854. The candidates spoke in each of Illinois's nine congressional districts. They had already spoken in the state capital of Springfield and in the state's largest city of Chicago within a day of each other, so they decided that their future joint appearances would be held in the remaining seven congressional districts. Since Douglas was the incumbent, he had very little to gain from these debates. However, Lincoln, only a one-term U.S. Representative (congressman) a decade before, was gaining support, having spoken the day after Douglas spoke in Chicago, and thus presenting a rejoinder Douglas could not answer back with a rebuttal. Each debate lasted about three hours, with each candidate speaking for thirty minutes, followed by a ninety-minute response and a final thirty-minute rejoinder by the first candidate. As the incumbent, Douglas spoke first in four of the debates, and Douglas and Lincoln alternated who spoke first at the remaining debates. They were held outdoors, weather permitting, from about 2 to 5 p.m.

The Freeport Doctrine was articulated by Stephen A. Douglas on August 27, 1858, in Freeport, Illinois, at the second of the Lincoln-Douglas debates. Former one-term U.S. Representative Abraham Lincoln was campaigning to take Douglas's U.S. Senate seat by strongly opposing all attempts to expand the geographic area in which slavery was permitted. Lincoln tried to force Douglas to choose between the principle of popular sovereignty proposed by the Kansas-Nebraska Act (which left the fate of slavery in a U.S. territory up to its inhabitants), and the majority decision of the United States Supreme Court in the case of Dred Scott v. Sandford, which stated that slavery could not legally be excluded from U.S. territories (since Douglas professed great respect for Supreme Court decisions, and accused the Republicans of disrespecting the court, yet this aspect of the Dred Scott decision was contrary to Douglas's views and politically unpopular in Illinois). Douglas responded that, despite the court's ruling, slavery could be excluded from any territory by the refusal of the people living in that territory to pass laws favorable to slavery. Likewise, if the people of the territory supported slavery, legislation would provide for its continued existence.

John Cabell Breckinridge (January 16, 1821 – May 17, 1875) was an American politician who served as the 14th vice president of the United States, with President James Buchanan, from 1857 to 1861. Assuming office at the age of 36, Breckinridge is the youngest vice president in U.S. history. He was also the Southern Democratic candidate in the 1860 presidential election, losing to antislavery Republican candidate Abraham Lincoln.

Breckinridge was born near Lexington, Kentucky, to a prominent local family. After serving as a noncombatant during the Mexican–American War, he was elected as a Democrat to the Kentucky House of Representatives in 1849, where he took a pro-slavery stance. Elected to the U.S. House of Representatives in 1851, he allied with Stephen A. Douglas in support of the Kansas–Nebraska Act. After reapportionment in 1854 made his re-election unlikely, he declined to run for another term. He was nominated for vice president at the 1856 Democratic National Convention to balance a ticket headed by James Buchanan. The Democrats won the election, but Breckinridge had little influence with Buchanan, and as presiding officer of the Senate, could not express his opinions in debates. He joined Buchanan in supporting the proslavery Lecompton Constitution for Kansas, which led to a split in the Democratic Party. In 1859, he was elected to succeed Senator John J. Crittenden at the end of Crittenden's term in 1861.