Membership in the Sons of Confederate Veterans is open to all male descendants of any veteran who served honorably in the Confederate armed forces. Membership can be obtained through either lineal or collateral family lines and kinship to a veteran must be documented genealogically. The minimum age for full membership is 12.
To obtain proof of his service, contact the archives of the state from which the soldier fought and obtain a copy of the veteran's military service record. All Southern state's archives have microfilm records of the soldiers who fought from that state, and a copy of the information can be obtained for a nominal fee. In addition, the former Confederate states awarded pensions to veterans and their widows. All of these records contain a wealth of information that can be used to document military service.
Please note that finding someone listed in the Broadfoot Roster with the same name as your ancestor does not constitute proof (John Jones from Tennessee). You must use accepted standards of genealogical research to demonstrate that the two men are, in fact, the same.
The SCV has a network of genealogists to assist you in tracing you ancestor's Confederate service.