NOTE: All names have been changed.
Bob's DNA test had several close cousin matches that he could not figure out. Working through the matches and putting people together in time and place, I was able to identify a previously unknown grandmother - Gramma New.
The cookies Bob loved were baked by his 'paper trail' grandmother - Gramma Gee. He never knew genetic Gramma New. Gramma New was part of a large family, so Bob has many New half cousins.
Emotionally, this was difficult. Bob's Gee family was Quaker and well documented. The family had a strong 'Gee' identity. There was no church record about this dalliance.
Finding the relationship was difficult, but once found, the autosomal matches fit together nicely. Most researchers would stop here. But I asked Bob to do a Y-DNA test.
Unlike many early families, the Gee family was small. Many members were childless, or had just one or two children. Bob had no autosomal DNA matches in this line, but because my paper research had documented the small family, I was not surprised. All his close family matches were linked to known lines, there were no more mystery matches. Men in the Gee family tend to look alike. Bob looks like his father, who mirrored his father. Bob's sons are easily identified, they look like Bob.
Nevertheless, a Y-DNA test seemed like a good idea. He wanted to prove his surname. When his Y test came back, it was gut wrenching. His well established and documented Gee surname was not his. He was a New.
His New grandmother, with some of her siblings, had moved into the area from a distant state. They appeared to come for work. There was no indication she had other family in the area. The new cousins definitely came from one couple, who remained in the original state. The New female was definitely the link to Bob.
Only men have a Y chromosome. There was a New male in his line.