In the late 1840s what led to the question of whether slavery should expand to the territories?

Answer 1

Wilmot Proviso Seeks to Limit Slavery Americans had long avoided the troubling issue of the expansion of slavery. But when the United States gained new territories as a result of the Mexican War in the late 1840s, the nation had to decide whether to admit these lands as slave territories or free territories. The delicate balance of power between North and South -- free and slave -- depended on this decision. During the early days of the Mexican War, Pennsylvania congressman David Wilmot had predicted the dilemma. He proposed a law stating, "neither slavery nor involuntary servitude shall ever exist in any" lands won from Mexico. South- erners angrily denounced the Wilmot Proviso. The northern-dominated House of Representatives approved the law, but the Senate voted it down. right out of my history book hope that help you