If I could live my life over again, I think I would want this person’s job.

With millions of Americans obsessively tracing their roots, Ms. [Maureen] Taylor has emerged as the nation’s foremost historical photo detective. During a recent meeting of the Maine Genealogical Society, attendees lined up a dozen deep as she handled their images with a cotton glove and peered at the details through a photographer’s loupe. One man offered a portrait photo and asked if it could be of his great grandmother, who died in 1890. "It’s not," Ms. Taylor said after about 15 seconds; she’d dated the hairstyle and billowy blouse to the early 20th century. When another attendee asked why her great-great-grandfather was wearing small hoops in his ears in a portrait, Ms. Taylor explained, "He was in the maritime trade."

Ms. Taylor, who charges $60 an hour, has learned to spot details that reveal not only a photo’s period, but the story behind it. A broom at the feet of a couple in a mid-19th-century portrait, for instance, often marks it as a wedding picture. A photograph of a baby in a carriage from the 1860s might not be a birth announcement, but a death card; in that period of high infant mortality, dead infants were commonly photographed in carriages. A 19th-century woman with unusually short hair may have had scarlet fever, because it was common to shave a victim’s head.

It’s kind of like forensic work, with old photographs and a knowledge of cultural history.

Maureen Taylor has a website, and an interesting blog, too.