The National Archives at Atlanta, a repository for the historically valuable noncurrent records of the Federal Government, is a major source for research for the study of the Civil War. One of the National Archives and Records Administration's 13 regional archives, it maintains historical records of federal agencies in Alabama, Florida, Georgia, Kentucky, Mississippi, North Carolina, South Carolina, and Tennessee. The records contain valuable historical information relating to soldiers, battles, civilians, and the Union and Confederate governments. Records in the National Archives at Atlanta are not arranged according to subject but are kept in numbered record groups established for the government agencies that created or received them. Although arrangement by record group (abbreviated RG) makes subject access more difficult at times, it preserves the organizational and contextual integrity of the records, making them more easily understood. Some records are available on microfilm while others are textual and must be viewed in the Textual Research Room.