Confederate soldier date of death

I am looking for a date and place of buriel for John N P Wiggs.He was a confederate soldier and was on the 1870 census in Greene County. I know parts of Greene and Randolph counties were taken to form Clay County. I have not found any information in Greene County so am starting on Clay now.
The family thinks he died around 1880 but has no record of it.Also, we do not know where he is buried.