Aaron Meissner was a German immigrant abolitionist who served in the 2nd Missouri Infantry Regiment during the American Civil War. He and several other German Lutheran immigrants in St. Louis formed several Unionist regiments ta the start of the war and participated in the Camp Jackson Affair, the Battle of Pea Ridge, the Siege of Corinth, the Kentucky campaign, and the Chattanooga campaign before being mustered out in October 1864.