There are quite a few articles about how the records were prepared. I bought one at a local yard sale. The only surviving regimental and company records not used in creating CSRs are those which did not fall into Federal hands. In other words, it's possible to find a roll or two in a museum or state archives that became part of the collection after the CRSs were created. During the compilation project, Southern states offered every wartime document they had available to Federal authorities. General Ainsworth would not accept post-war rolls and papers because Congress authorized compilation of wartime records only.