Final answer:
The correct answer is option 1. Abraham Lincoln did not support the Kansas-Nebraska Act in its final form, which was proposed by Stephen Douglas and might have allowed slavery in Kansas and Nebraska.
Step-by-step explanation:
The person who did not strongly support the Kansas-Nebraska Act in its final form was Abraham Lincoln. Stephen Douglas, who proposed the Act, initially saw it as a way to boost his presidential prospects by allowing the possibility that slavery might be permitted in Kansas and Nebraska based on popular sovereignty.
However, it stoked conflict and further inflamed sectional tensions, and Douglas later had to oppose President Buchanan's support of the pro-slavery Lecompton Constitution to keep faith with northern Democrats and maintain his political reputation. John C. Calhoun was a strong proponent of states' rights and slavery but had passed away in 1850, four years before the Act. James Buchanan attempted to sway both sides of the slavery debate and distanced himself from the Act's controversy.