The records for Civil War soldiers and sailors are found at NPS.gov. The website also houses a comprehensive list of cemeteries, monuments and battles having to do with the Civil War.
Civil War records of over 6 million soldiers and over 18,000 African American sailors are in The Civil War Soldiers and Sailors System (CWSS), which is maintained by the National Parks Service and made available at their website. The system also contains the histories of over 4,000 Union and Confederate Regiments. The records of prisoners held at the Confederates' Fort McHenry, and the Unions' Andersonville Prison camp are also held in the system and are available online through the National Parks Service.