He helped organize the 20th Alabama Infantry and became one of its first officers. He was captured a few times by union troops escaping every time or took part in a exchange of troops was freed. Usually every time after his exchange he was promoted a rank and eventually rose to the rank of Brigadier General. He was given brigade control of the army of Tennessee. He participated in the Confederates defense of the deep south during Shermans march to the sea. Pettus was sent to the defense of Columbia, South Carolina. When the Confederacy surrendered to the Union Pettus received a pardon from the United States Government.
After the war Pettus returned to his life of law practice in Selma, which is when he moved into this historic house. He led the Klu Kux Klan while living in Selma as the grand master. During this time he also served in the United States senate first in 1897 and later in 1903. He died in Hot Springs, California in 1907, His body is buried in Live Oak Cemetery in Selma. His legacy lives on with a bridge in Selma, Alabama being named after him.