Final answer:
The Constitution protected slavery to maintain support from southern states for the new Constitution and to preserve the union, despite the conflict with the principles of liberty.
Step-by-step explanation:
Historians suggest that the Constitution protected slavery for several reasons. At the time of the Constitutional Convention, there was an opportunity to address the issue of slavery directly. However, instead of confronting it, the framers of the Constitution crafted compromises that appeased southern states and ensured their support for the new document. The contentious Three-Fifths Compromise and the temporary continuation of the international slave trade were amongst the most significant elements that indicated the Constitution's protection of slavery.
Moreover, the Constitution's Article IV included a clause that required states to return those pursuing freedom back to the states from which they fled, impeding the enslaved from finding liberty in states where slavery was abolished. This protection extended to southern economic interests, as it allowed the continued internal trade of enslaved people.
The need to create a 'more perfect union' was weighed against the stark reality of an economy that was dependent on enslaved labor in the South. Consequently, the founding fathers incorporated protections for slavery into the Constitution to maintain the union, despite the inherent contradiction with the principles of liberty and equality that they espoused.