Secession and the Confederacy's core ideology centered around states' rights and slavery.
They believed in limited federal, but expansive states' rights and the importance of maintaining a social and economic structure based on enslaved peoples to sustain their agricultural-based Southern economy, particularly the institution of slavery.
While not explicitly stated in its Constitution, slavery and protecting the interests of large plantation owners who depended on them were crucial factors fueling Southern grievances that culminated in secession when Abraham Lincoln and the Republican Party, both openly critical of slavery, ascended to dominance in American politics from 1860 onwards.
In summary, the core beliefs and principles championed by the Confederate States can be distilled into:
_Limited federal power_, _expansive states' rights_, a strong emphasis on _white supremacy_, a staunch _protection of slavery_.