Final answer:
The Wilmot Proviso, admission of California, and the Missouri Compromise all dealt with the controversial issue of slavery's extension in the U.S. territories, highlighting the deepening sectional tensions leading up to the Civil War.
Step-by-step explanation:
The Wilmot Proviso, admission of California into the Union, and the Missouri Compromise all centered on the contentious issue of the extension of slavery into new and existing territories of the United States. Southerners particularly opposed the Wilmot Proviso, which sought to prohibit slavery in territories acquired from Mexico, as it would limit their political power and jeopardize the institution of slavery. The Missouri Compromise, on the other hand, drew a boundary for slavery to the north-south axis but was challenged by some for the application of popular sovereignty in all territories. The rapid push for statehood from California following the gold rush and its desire to enter the Union as a free state added urgency to the debate, leading to compromises that sought to maintain a delicate balance between free and slave states.
Debates over these issues extended into larger discussions on the rights of states versus federal authority and foreshadowed the growing sectional tensions that eventually led to the American Civil War. While the Wilmot Proviso directly proposed barring slavery, others like the Missouri Compromise and the Compromise of 1850 attempted to create a balance, but this balance was inherently unstable due to the moral, economic, and political implications surrounding the institution of slavery.