He resigned his ecclesiastical position to become a major-general in the Confederate States Army, when he was called "Sewanee's Fighting Bishop".

Recognizing his familiarity with the Mississippi Valley, Confederate president Jefferson Davis commissioned his elevation to a high military position regardless of his lack of prior combat experience.

[1] Polk briefly attended the University of North Carolina at Chapel Hill before entering the United States Military Academy at West Point.

Moore agreed to ordain Polk as a deacon in April 1830; however, on a visit to Raleigh in March, it was discovered that he had never been confirmed as an Episcopalian.

[2] Polk's foundational legacy at Sewanee is remembered through his portrait Sword Over the Gown, painted by Eliphalet F. Andrews in 1900.

Gen. Gideon Johnson Pillow, and his superior, Gen. Albert Sidney Johnston, commander of Confederate forces in the Western Theater.

[12] Polk's command saw its first combat on November 7, 1861: the minor Battle of Belmont between troops under Pillow and U.S. soldiers under Brig.

In April 1862, Polk commanded the First Corps of Albert Sidney Johnston's Army of Mississippi at the Battle of Shiloh.

He continued in that role for much of the year under Beauregard, who assumed command following the death of Johnston at Shiloh and then under Gen. Braxton Bragg.

At the Battle of Perryville, Polk's right wing constituted the main attacking force against Maj. Gen. Don Carlos Buell's Army of the Ohio, but Polk was reluctant to attack the small portion of Buell's army that faced him until Bragg arrived at the battlefield.

"[16] After Perryville, Polk began a year-long campaign to get Bragg relieved of command, hoping to use his close relationship with President Davis to accomplish his goal.

Bragg was also unsuccessful in resisting Rosecrans's advance in the Tullahoma Campaign, which began to threaten the important city of Chattanooga.

In the face of Rosecrans's expert maneuvering of his army, Polk counseled Bragg to retreat rather than stand and fight in their Tullahoma fortifications.

He was infuriated when Polk's division under Maj. Gen. Thomas C. Hindman failed to attack an isolated U.S. Army corps at Davis's Cross Roads as ordered on September 11.

Two days later, Polk disregarded orders from Bragg to attack another isolated corps, the second failed opportunity.

He failed to inform his subordinates of the plan, and his wing was late in attacking, allowing the U.S. defenders time to complete their field fortifications.

Bragg wrote to President Davis, "Gen'l Polk by education and habit is unfit for executing the plans of others.

Although Polk protested the "arbitrary and unlawful order" to the Secretary of War and demanded a court of inquiry, he was not restored to his position.

Polk unsuccessfully attempted to oppose Maj. Gen. William Tecumseh Sherman's raid against Meridian, Mississippi, in February 1864.

By using successive flanking maneuvers, Sherman forced Johnston to withdraw his army from strong defensive positions to protect the Confederate line of communication.

On June 14, 1864, Polk was scouting enemy positions near Marietta, Georgia, with his staff when he was killed in action by a U.S. 3-inch (76 mm) shell at Pine Mountain.

[25] The artillery fire was initiated when Sherman spotted a cluster of Confederate generals — Polk, William J. Hardee, and Johnston, with their staffs — in an exposed area.

His deficiencies as a commander and his personal traits of stubbornness and childishness had played no small role in several of the army's disasters in earlier times.

Although his record as a field commander was poor, Polk was immensely popular with his troops, and the Army of Tennessee deeply mourned his death.

His friend Bishop Stephen Elliott of Georgia presided at the service, delivering a stirring funeral oration.

[34] Polk's portrait, done by Cornelius Hankins, was donated to Christ Church Cathedral in Nashville, Tennessee, by his grandson W. Dudley Gate, in 1963.