Final answer:
Southern slaveholders and their supporters were strongly opposed to ending slavery, defending it against abolitionist efforts. They argued that wage labor in the North was worse than Southern slavery, and conflicts over this issue helped lead to the Civil War.
Step-by-step explanation:
The group that was vehemently opposed to ending slavery despite sometimes trading with slaves and resenting planters were the southern slaveholders and their sympathizers. These individuals fiercely defended the institution of slavery as a fundamental part of their economic and social order, clashing directly with the abolitionist movement that sought to end the practice. Often, they argued that the wage labor system in the industrial North, which they called wage slavery, was worse than the conditions of enslaved individuals in the South, a view meant to counter abolitionist critique and justify their way of life.
Tensions between those defending slavery and those opposing it escalated into the notion of an irrepressible conflict, as described by William H. Seward in 1858, highlighting the growing divide between the North and South over the issue. The debate over the moral, economic, and political aspects of slavery became one of the leading causes of the American Civil War, as the two regions had become deeply entrenched in their respective stances on the institution of slavery and its expansion into new territories.