The Western Theater includes battles and campaigns by Western and Trans-Mississippi armies. These include various Union armies, especially the Army of the Cumberland and the Army of the Tennessee. Part 2 also features operations by the Confederate armies of Tennessee, Mississippi, the West, and the Southwest. The Western Theater includes the midwestern states of Ohio and Indiana, the "middle South" states of Kentucky and Tennessee, and the Deep South-Louisiana, Mississippi, Alabama, and Georgia. Trans-Mississippi states include Missouri, Arkansas, Texas, and the New Mexico territory.