MAP 13.1 Early Civil War Battles, 1861–1862 In 1861 and 1862, the Confederate army stunned Union forces with a series of dramatic victories in Virginia and Missouri. However, the Union army won a crucial victory at Antietam (Sharpsburg); gained control of Confederate territory in Tennessee, Arkansas, and Mississippi; fended off Confederate efforts to gain New Mexico Territory; and established a successful naval blockade of Confederate ports.