John J. Pettus was born in 1813 in Tennessee and raised in Alabama, where he was educated at home by his mother. He relocated to Mississippi in 1835, studied law, and established a legal practice. Pettus began his political career in the 1840s, representing Kemper County in the Mississippi House of Representatives and later serving in the Mississippi Senate. He became acting governor in 1853 and was elected governor in 1859, advocating for secession and the establishment of a Southern Confederacy. During the Civil War, Pettus faced significant military and economic challenges, including shortages and reliance on illegal trade, while maintaining a state military force. After the war, he took the oath of allegiance but fled to avoid prosecution and died in 1867.

John J. Pettus's political identity is marked by a rigid defense of slavery and Southern secession, paired with surprising economic pragmatism during dire circumstances. His advocacy for secession and a Southern Confederacy was driven by an unyielding commitment to maintaining slavery, yet he reluctantly permitted illegal cotton trade with Union forces to alleviate economic hardships. Pettus's rhetoric consistently framed issues through a lens of white supremacy and regional loyalty, while his actions revealed a calculated approach to navigating the Confederacy's challenges.