Final answer:
The most unpopular provision in the Confederate draft law exempting big slave owners from the draft was known as the 'Twenty Negro' provision.
Step-by-step explanation:
The most unpopular provision in the Confederate 1862 draft law exempting big slave owners from the draft was known as the 'Twenty Negro' provision. According to the Conscription Act passed in April 1862, any man who owned more than 20 slaves was exempt from the draft. This provision favored wealthy slave owners and led to resentment among poorer whites who were not exempt from military service.