Upheaval at the 1860 Democratic Convention: What Happened When a Party Split

Some issues are too fundamental for a party to withstand, and the consequences can last for a generation.

This year is remembered as landing one of America’s most revered and consequential presidents in office. But Abraham Lincoln’s election, and his subsequent assault on slavery, might not have happened had the Democratic Party not been in such disarray. This series was produced by Matt Spolar, in partnership with Politico.

For teachers
  • Producer: Matthew Spolar
  • Editor: Brian Kamerzel
  • Associate Producer: Victor Couto

For Educators


This four-minute video explores the causes and consequences of the Democratic Party’s division into two parties following the Democratic national convention of 1860. After rejecting Stephen A. Douglas’s failed attempt to reconcile the Northern and Southern factions of the party with his doctrine of “popular sovereignty,” the Southern delegates walked out of the convention. That decision led to the election of Abraham Lincoln, the Civil War, and 50 years of Republican dominance in national politics. A concise summary of the unusual events that allowed Abraham Lincoln to win the election of 1860, the video fits into any sequence of lessons on the factors leading to secession and the Civil War.

Background reading

Political scientist V.O. Key introduced the concept of critical elections into the study of voter behavior in 1955. Key’s main argument was that certain elections result in a set of sharp changes in party ideology, issues, party leaders, regional and demographic bases of power. The election of 1860 is one of these critical elections. It ushered in a period of Republican Party dominance between 1860-1912.

The 1860 Democratic Convention provided a textbook illustration of what happens when a party splits. The Democratic Party had been the dominant political party of decades, but that solidarity began to crumble over the volatile issue of whether to introduce slavery in the western territories. Southern Democrats sought to extend slavery into every new state admitted to the union, while many Northern Democrats were opposed. Front-runner Senator Stephen A. Douglas of Illinois hoped to hold the party together by advocating a compromise position that would allow the residents of new states to determine the issue of slavery for themselves. But delegates of seven deep Southern states refused to support him, and attempted to block Douglas’s nomination at the party convention. When that failed, the pro-slavery delegates held their own convention, nominated their own candidate, Vice-President John C. Breckinridge of Kentucky, and endorsed a pro-slavery platform. The split in the Democratic Party led to electoral disaster for both party factions, as it contributed to the rise of the anti-slavery Republican Party and its little-known candidate, Abraham Lincoln. With only brief interruptions, the Republicans would hold the White House until 1912.

Lesson Plan 1: Election of 1860 – Slavery Splits the Democrats

Students will learn how the issue of slavery caused a split in the Democratic Party that led to the Civil War and paved the way for 50 years of Republican dominance in national politics.


Students will:

  • Analyze and assess the causes and consequences of the division within the Democratic Party over the issue of slavery that led to its defeat in the presidential election of 1860.
  • Summarize, compare and contrast, and draw logical inferences from primary source documents regarding the 1860 election.
  • Collaborate with peers in pairs and/or small groups to discuss, analyze, and assess text and visual primary source documents.
  • Develop a position and present a viewpoint based on historical evidence.
Essential questions
  • To what extent did growing sectional tension and turmoil concerning slavery affect (or determine) the selection of presidential candidates and the outcome of the election of 1860?
  • To what extent did the issue of extension of slavery undermine the unity and lead to the defeat of the Democratic Party in 1860?
  • How did the results of the presidential election of 1860 reflect the growing sectional discord and disunion of the United States? Did the outcome of the election of 1860 foment and incite southern secession and the outbreak of the Civil War?
  • Common Core State Standards
    • CCSS.ELA-LITERACY.RL.9-10.4:Determine the meaning of words and phrases as they are used in the text, including figurative and connotative meanings; analyze the cumulative impact of specific word choices on meaning and tone (e.g., how the language evokes a sense of time and place; how it sets a formal or informal tone).
    • CCSS.ELA-LITERACY.RH.9-10.9:Compare and contrast treatments of the same topic in several primary and secondary sources.
    • CCSS.ELA-LITERACY.RH.11-12.2:Determine the central ideas or information of a primary or secondary source; provide an accurate summary that makes clear the relationships among the key details and ideas.
    • CCSS.ELA-LITERACY.RH.11-12.7:Integrate and evaluate multiple sources of information presented in diverse formats and media (e.g., visually, quantitatively, as well as in words) in order to address a question or solve a problem
  • National Council for the Social Studies C3 Framework
    • D1.4.9-12.Explain how supporting questions contribute to an inquiry and how, through engaging source work, new compelling and supporting questions emerge.
    • D2.His.1.9-12.Evaluate how historical events and developments were shaped by unique circumstances of time and place as well as broader historical contexts.
    • D2.His.5.9-12.Analyze how historical contexts shaped and continue to shape people’s perspectives.
    • D3.1.6-8.Gather relevant information from multiple sources while using the origin, authority, structure, context, and corroborative value of the sources to guide the selection.
    • D4.1.6-8.Construct arguments using claims and evidence from multiple sources, while acknowledging the strengths and limitations of the arguments.
  • AP Government and Politics
    • Unit 5: Political Participation