A biography of Rev. John Wesley Caughlan—a Provost Marshal in Missouri during the Civil War—includes this story, related by his son Fred.
He was sent to draft a young man. When they went in the parents said he was not old enough, so father demanded a family record and asked for the family Bible. After a lot of searching it was produced and showed signs of having been altered. A closer look showed that he and his younger brother were only two months apart in age. Father asked “how did this happen?” They said “they didn’t know, but it did.” They took the boy along. [Link]