There is no record of him being captured, paroled, etc. There seems to be a mixed bag of what happened to men of the 9th. Why some were paroled and others forwarded to prison is a mystery.

Perhaps this site might explain: http://www.acadiansingray.com/9th%20Bn.%20Inf.htm

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Captain R. B. Chinn, Company C, 9th Louisiana Infantry Battalion, Commanding Regiment, captured at Port Hudson July 9, 1863, sent to Provost Marshal, New Orleans July 13 on Steamer Zephyr, shipped to Fort Columbus, New York Harbor October 10 and forwarded to Johnson's Island, Ohio October 13, transferred to Baltimore, Md. February 9,1864, forwarded to Point Lookout, Maryland, thence to Fort Delaware, Del., paroled October 6, 1864 and transferred to Point Lookout, Maryland for exchange, forwarded to Cox Wharf, James River, Virginia arriving October 15, 1864, no further records

There was a Private S. J. Bankston, Company C who is recorded as having been paroled at Port Hudson, July, 1863, no further information. In Company D is a Private Spencer M. Bankston who enlisted August 1, 1862 at Ponchatoul, La. and was paroled as a 1st Corporal at Port Hudson, La., July 10, 1863, no further records

M320: Compiled Service Records of Confederate Soldiers Who Served in Organizations from the State of Louisiana