The next day, the battery was present at the Battle of Big Black River Bridge. The unit's exact placement during the fight is variously reported. The historian Philip Thomas Tucker reports that a portion of the battery was assigned to the Confederate front line, and the rest on the far side of the river. Tucker then states that when the Confederate line was broken by a Union assault, that front line portion of the battery lost its cannons, as the battery's horses had been sent to the other side of the Big Black River. Other sources say the battery was positioned entirely on the far side of the river. The historian James McGhee says the two pieces damaged at Champion Hill were not present at this action. Either way, the portion of the battery across the river helped cover the Confederate retreat, and entered the fortifications of Vicksburg. During the siege of Vicksburg, some of the artillerymen served as sharpshooters due to a shortage of cannons. On May 22, the battery helped repulse Union attacks, at one point using double-shotted ammunition. Over the course of the siege, the unit suffered either ten or thirteen casualties during a 47-day span of mostly continuous fighting. The Confederates surrendered Vicksburg on July 4, and Landis's Battery was captured at this time. The 37 men left in the battery were released on parole until they were exchanged; they were also ordered to Demopolis, Alabama. On October 1, Landis's Battery and Wade's Missouri Battery were absorbed by Guibor's Battery; Landis's Battery ceased to exist as a separate unit. About 75 men served with the battery throughout the war. The unit reported the deaths of 22 of its members. Of these, fifteen were the result of battle, while six died from disease and one member of the battery was murdered.