Final answer:
The doctrine of interposition was a pre-Civil War theory that states could invalidate federal actions they considered unconstitutional, challenging federal supremacy and leading to national disunity. It was problematic as it could undermine national law and cohesion, contributing to the rise in tensions that sparked the Civil War. President Lincoln's initial stance on slavery was to allow it to die out gradually, rather than pushing for immediate abolition.
Step-by-step explanation:
The pre-Civil War doctrine of interposition refers to a theoretical right claimed by the states to interpose themselves and invalidate any federal action they deemed unconstitutional. Rooted in the ideas of Thomas Jefferson and James Madison as seen in the Virginia and Kentucky Resolutions of 1798, the concept suggested that states, being parties to the federal compact, held the authority to determine the extent of federal power.
However, a major issue with this doctrine was its challenge to the supremacy of federal laws and the Constitution, which could undermine the national cohesion and the rule of law. It effectively placed individual states above the federal judiciary system, which the Constitution establishes as the final arbiter of its own interpretation. With each state interpreting laws differently, this could lead to a disunited nation with inconsistent laws and policies, which was a fundamental aspect of the disputes leading up to the Civil War.
Although President Abraham Lincoln disliked slavery and hoped it would end eventually, he did not initially plan to abolish it through the Civil War. He believed immediate abolition was too radical and unconstitutional. According to the doctrine of interposition, states could have attempted to countermand Lincoln's later anti-slavery measures. However, this undermined the ability to form a more unified policy towards issues such as slavery and ultimately contradicted the idea of a single, indivisible nation under a federal system.