I have an ancestor who was 'court martialed' during the Civil War according to his service records cards. The end result was a reduction in rank from coporal to private. He was discharged at the end of the war with the rest of his unit. Some years later his descendants filed for a pension, but it appears as if they were denied. I would like to know if or where I would be able to get court martial records for CW soldiers who served in the Union Army. Is this even a resource open to descendants?