After Bowen withdrew from the Port Gibson area, the 1st and 4th Missouri (Consolidated) was next engaged at the Battle of Champion Hill on May 16. Bowen's division was under the commanded of Lieutenant General John C. Pemberton, and Pemberton had aligned his troops near Champion Hill to try to stop Grant's advance towards Vicksburg. A strong Union assault broke the left flank of the Confederate line, and Cockrell's brigade was sent to try to prevent a complete collapse of the line. The 1st and 4th Missouri (Consolidated) formed on the right end of Cockrell's line, and soon came under heavy Union fire. The regiment then charged the Union position, buying time for Brigadier General Martin E. Green's Confederate brigade to arrive. Together, the brigades of Cockrell and Green, including the 1st and 4th Missouri (Consolidated), charged the Union line, which was driven back some distance. After driving Union troops from a crossroads and recapturing some cannons the Confederates had lost earlier in the battle, the Confederates charged towards the Champion family plantation, which was on a hill and was a key terrain feature. Brigadier General Alvin P. Hovey's Union division was broken by the Confederate charge, and the Confederates kept pressing forward. However, Union reinforcements and a strong line of artillery blunted the charge, and Bowen's men were forced to give up the ground they had gained. The 1st and 4th Missouri (Consolidated) lost six flagbearers at Champion Hill. In total, the regiment lost 46 men killed, 80 wounded, and 52 missing in the fight, for a total of 178.