Final answer:
The Wilmot Proviso highlighted strong sectional differences by proposing to ban slavery in territories acquired from Mexico, gaining support from the North and opposition from the South.
Step-by-step explanation:
The Wilmot Proviso was a significant piece of legislation that revealed strong sectional differences by proposing the prohibition of slavery in new territories acquired from Mexico.
It gained support largely from the North and passed the House of Representatives but failed in the Senate, where Southern opposition was strong due to fears that it would limit Southern influence in national politics and potentially lead to restrictions on slavery within the states themselves. The debate on the proviso showcased the growing divide between the North and South over the issue of slavery, contributing to the increasing tensions that would eventually lead to the Civil War.