Maj. Gen. John Pope's main force and Trimble played a major role in the Battle of Manassas Station Operations, seizing a critical supply depot in Pope's rear. Trimble's forced march and action at Manassas Station received praise from Jackson, who said it was "the most brilliant that has come under my observation during the present war." Pope was forced by this maneuver into attacking Jackson's strong defensive positions and suffered a severe defeat in the Second Battle of Bull Run. Trimble was wounded in the leg during the battle on August 29, resulting in an injury so severe that there was speculation that he was hit with an explosive bullet. Although Trimble avoided the amputation of his wounded leg, his rehabilitation proceeded slowly. For months after, doctors periodically found bone fragments that had to be extracted. By November, he developed camp erysipelas and a probable case of osteomyelitis, and his ambitions for elevation to division command were on hold until he was well enough to return to active duty. He made his desire for promotion abundantly clear to his colleagues, and in one instance before the army moved north to Manassas, he was quoted as saying (probably humorously), "General Jackson, before this war is over, I intend to be a Major General or a corpse!" Jackson wrote a strong letter of recommendation, although he tempered it by including the sentence "I do not regard him as a good disciplinarian." Trimble engaged in a letterwriting campaign from his sick bed to obtain his promotion and to challenge Jackson's claim. He wrote to Adjutant General Samuel Cooper, "If I am to have promotion I want it at once and I particularly request, that my date may be from 26 August, the date of the capture of Manassas." (During this period Trimble also feuded with Maj. Gen. J.E.B. Stuart about their conflicting reports of the battle and who bore primary responsibility for the seizure of the Union supply depot.) Trimble was eventually promoted to major general on January 17, 1863, and assigned to the command of Jackson's old division, but he continued to be unable to command in the field due to his health. At the Battle of Chancellorsville Brig. Gen. Raleigh E. Colston, as the senior brigadier general, commanded Trimble's division. A recurrence of illness forced him to turn over his division command in the Second Corps to Maj. Gen. Edward "Allegheny"