"I felt obligated to break the news to the family, " and "it wasn't well-received, " says Dr. Hibben.

WSJ: When a Genealogy Hobby Digs Up Unwanted Secrets

Instead, she learned that her ancestor never saw action and was discharged after less than a year for a hernia caused by "excessive marching and a fall over a log, " says Dr. Hibben, a Lake Mathews, Calif.

WSJ: When a Genealogy Hobby Digs Up Unwanted Secrets

Jean Wilcox Hibben set out to explore a story she heard as a child about a great-grandfather, a scholar and musician who was heralded for serving as Union General William Sherman's scribe during his historic "march to the sea" and capture of Savannah, Ga.

WSJ: When a Genealogy Hobby Digs Up Unwanted Secrets