On 19 July 1864, the day before the Battle of Peachtree Creek, Dilworth's brigade sustained 245 casualties while capturing a hill that dominated the Howell's Mill crossing. This was during a movement where Thomas' army crossed Peachtree Creek and began taking positions on its south side. By the next day, Palmer had the XIV Corps entrenched. Instead, the Confederates attacked Hooker's XX Corps and one division of the IV Corps and were repulsed. During the Battle of Utoy Creek, Palmer resigned his command in a dispute over rank; he was replaced in command of the XIV Corps by Davis. At the Battle of Jonesborough on 1 September, Davis' corps made a major assault. On the right, Brigadier General James D. Morgan's division (formerly Davis') charged with Dilworth's brigade on the right, Mitchell's in the center, and Colonel Charles M. Lum's brigade on the left. On the left were the divisions of Brigadier Generals Absalom Baird and William P. Carlin. The 125th Illinois was the center regiment of the 3rd Brigade, with the 22nd Indiana to its right and the 52nd Ohio to its left, and with the 85th and 86th Illinois in the second line. Dilworth was badly wounded at the start and replaced in command by Langley. It was the only successful frontal assault in the Atlanta campaign, capturing an entire Confederate brigade and part of another. Mitchell's and Dilworth's (Langley's) men captured Swett's Mississippi Battery.  