See http://www.csa-dixie.com/csa/gazette/jackson/dedicationoftombanvstonewallstatue.htm
This is an account of the dedication of the Army of Northern Virigina tomb on May 10, 1881. Since your ancestor died on August 2, 1880, his death predates the availability of the tomb.
Given the practices of the times, one of "his friends" may have had a family tomb which was available for use. I would still suggest browsing through the minutes of the ANV meetings (the organization was formed in 1874) and see if any notes were made on the death and burial of your ancestor. My wife's extended family includes members of the Army of Tennessee Confederate veterans group who were buried in a family tomb, but their death and burial noted in the records of that organization.
Is this query about Captain Joseph Henry Dale, Co. I, 15th Louisiana Infantry?
Hugh