Why did American argue over ban of the black slavery?

Answer 1

From its Founding up to the Civil War and then even beyond, many Americans argued, and often heatedly, over the institution of slavery simply because of the differing viewpoints that they took on it. Whether it should be banned or allowed, or otherwise dealt with in some compromise solution, was debated frequently because some strongly believed that it was wrong, while others saw nothing wrong with it -- with many viewpoints in-between taken by many others.