The institution of slavery had been deeply entrenched in American society since the colonial era, and it played a crucial role in the economy of the southern states. The cotton industry, for example, was heavily reliant on slave labor, and many white Americans benefited from the profits generated by this industry. Additionally, many people believed in the concept of white supremacy, which held that people of European descent were superior to other races and therefore justified the enslavement of African peoples.
Furthermore, the issue of slavery was complicated by economic and political factors. Many politicians were reluctant to take a strong stance against slavery for fear of alienating southern voters or upsetting the delicate balance of power between northern and southern states. Some northerners who opposed slavery were also hesitant to take action because they feared it could lead to social and economic upheaval.
It was not until the Civil War that a significant number of people in the U.S. began to actively oppose slavery and fight for its abolition. Even then, it took a long and bloody conflict, as well as the tireless efforts of abolitionists and other activists, to ultimately bring an end to this brutal institution.