Being promoted to the rank of major general on October 27, 1862, Forney participated in the Battles of First Bull Run and Vicksburg before being captured.

[2] John Horace Forney was appointed to the United States Military Academy at West Point, New York and graduated in 1852,[1] twenty-second in his class.

[3] Forney resigned his commission on January 23, 1861, and entered the Confederate Army as colonel of the Alabama Artillery, then as a captain of infantry on March 14, 1861 and colonel of the 10th Alabama Infantry in the Army of the Shenandoah on June 21, 1861.

[1][2][4] He took command of the 5th Brigade and other Confederate forces in the Shenandoah Valley on June 21, 1861 while the remainder of that army moved to participate that same day at the First Battle of Bull Run until October 1861.

[2] At the end of the war, he returned to Alabama, where he was a farmer and civil engineer until his death in Jacksonville on September 13, 1902.