This one: 1. The Great Hanging (Gainesville, Texas, 1862): Confederate authorities and vigilantes in Cooke County, Texas convened an illegal tribunal that hanged over 40 local civilians suspected of Unionist sympathies (draft resisters who opposed secession)historycollection.com.
2. Centralia Massacre (Missouri, 1864): In September 1864, guerrillas led by William “Bloody Bill” Anderson – which included Frank and Jesse James – captured and murdered 23 unarmed Union soldiers pulled from a train in Centralia, Missourihistorycollection.com.
3.3. Fort Pillow Massacre (Tennessee, 1864): After Confederate cavalry under General Nathan B. Forrest overran Fort Pillow on April 12, 1864, they massacred Union troops who were attempting to surrender, including dozens of African American soldiers from the garrisonhistorycollection.com.
4. Saltville Massacre (Virginia, 1864): Following a battle at Saltville in October 1864, Confederate irregulars led by Champ Ferguson hunted down wounded Union soldiers (including members of the 5th U.S. Colored Cavalry) and murdered an estimated 45–50 injured prisonershistorycollection.com.