Final answer:
The "Cornerstone" speech demonstrated that the rebellion was built upon racism and slavery.
Step-by-step explanation:
The "Cornerstone" speech demonstrated that the rebellion was built upon racism and slavery. In this speech, Alexander H. Stephens, the Vice President of the Confederacy, explicitly stated that the cornerstone of the Confederacy was the belief in the inferiority of African Americans and the preservation of slavery. He defended secession as a means to protect and perpetuate the institution of slavery, which was the primary cause of the Civil War.
Learn more about Causes of the Civil War