As an addition to what George posted, I have done some research on the Minden Blues and this is what I have on Hadley. Incidentally, a descendant, Mark Hadley, of Bastrop, provided some of this information. He also has an image of Hadley. I have lost contact with him over the years but you may wish to seek him out.
Hadley, David Monroe, Private
David Hadley was born June 27th, 1844 in Cheneyville, LA to William Peter Gorsham Hadley and Lucinda Caroline Howard. The Hadleys later owned a foundry in Minden, LA. David was a student in Minden and not yet married when he was recruited to enlist at Minden on March 15th, 1862. He was present until captured at Rappahannock Station, VA on Nov. 7th, 1863. Sent to Point Lookout, MD, Hadley was exchanged on March 15th, 1864. David was shot through the neck at Spotsylvania Court House on May 12th, 1864. The wound also disabled his arm. He was furloughed home to Louisiana and never returned. David was working in a Hospital in Shreveport at the close of war. He had once credited John D. McIntyre with saving his life in battle. After the war, David married Sarah Elizabeth Crowell on Feb. 21st, 1866 in Magnolia, Arkansas. They had 8 children. Hadley died of apoplexy in Minden, LA on Oct. 27th, 1917 and is buried in the Antioch Cemetery in Minden.