Which consequence followed the Kansas-Nebraska Act?

• A. Northern Whigs and Democrats who opposed the act formed the Republican Party.
• B. The act intensified intersectional differences over the fugitive slave issue.
• C. Southern opponents of the act began the process of secession from the Union.
• D. The act undermined enforcement of key elements of the Compromise of 1850.

Answer: (A)

The key idea here is how the Kansas-Nebraska Act reoriented American politics by changing how slavery would be decided in new territories. By establishing popular sovereignty for Kansas and Nebraska and repealing the Missouri Compromise line, it opened a fierce dispute over whether slavery would expand into those areas. In response, anti-slavery factions in the North—primarily former Whigs and anti-slavery Democrats, along with Free-Soilers—broke with their old parties and formed a new political coalition: the Republican Party. This realignment became the defining consequence, signaling a national fight over slavery’s expansion that reshaped party politics for years to come. While the act did intensify sectional tensions and violence in Kansas (Bleeding Kansas), and secession came later, the formation of the Republican Party is the strongest, clearest consequence tied directly to the act.