In what state was the last Southern victory of the Civil War?
Texas - that coastal battle occurring AFTER the rest of the major fighting had stopped in Virginia and Georgia.
This requires a subjective answer. Many military historians cite the Confederate victory at Chancellorsville as the last major Confederate victory. In this three day battle beginning in May, 1862, the battle proved to be a complex three day conflict. The major event that brought victory to General Lee was the successful flank attack on Hooker's army.
The last battle fought in Tennessee during the Civil War, that was won by the Union was at Nashville, Tennessee in 1864. Tennessee was a state divided during the Civil War. The state seceded from the Union to side with the South, but many pro Union supporters stayed in the state to fight for the Union when the time came.
There were approximately 17 significant battles in the state of Mississippi in the Civil War. Nine of these were associated with the Battle & Siege of Vicksburg, and 8 more were scattered around the state. There were also a large number of smaller actions. The last significant battle in Mississippi was near Tupelo and Harrisburg and was a significant victory for the Union.
Oklahoma did not become a state until 1907. The US Civil War occurred from 1861 until 1865. So, the correct answer to this question is that Oklahoma did not fight on the Northern or the Southern side in the US Civil War. True, and yet, Stand Watie, BGen, CSA was the last Confederate General Officer to formally surrender on June 23, 1865 in Oklahoma, Indian Territory. Oklahoma was granted statehood on 16 November 1907.