And the argument that the south seceded over states’ rights is 100% valid. The northern states had been pushing their will on the south for quite a long time, and they were reaching a breaking point. At that time, as another commenter has noted, states were much more independent, and the federal government was not all powerful (like it is now). This was a situation where the federal government was forcing it’s will, which in this case was not a part of the constitution (yet), on the states. So it was very much about state’s rights. But again, the “winners” don’t like to give the losers any opportunity for redemption, and instead go out of their way to go on a historical smear campaign. Visual aid shown here.
In July 1897, Du Bois left Philadelphia and took a professorship in history and economics at the historically black Atlanta University in Georgia.  His first major academic work was his book The Philadelphia Negro (1899), a detailed and comprehensive sociological study of the African-American people of Philadelphia, based on the field work he did in 1896–1897. The work was a breakthrough in scholarship, because it was the first scientific study of African Americans and a major contribution to early scientific sociology in the .   In the study, Du Bois coined the phrase "the submerged tenth" to describe the black underclass. Later in 1903 he popularized the term, the " Talented Tenth ", applied to society's elite class.  Du Bois's terminology reflected his opinion that the elite of a nation, both black and white, was critical to achievements in culture and progress.  Du Bois wrote in this period in a dismissive way of the underclass, describing them as "lazy" or "unreliable", but – in contrast to other scholars – he attributed many of their societal problems to the ravages of slavery.