Before there was DNA testing, there were plenty of oopses, and careful work with genealogical resources can sometimes prove them. This oops goes back to the 1870s. My grandfather's aunt was a maiden school teacher, living in Peru VT. She had a son out of wedlock, who for the first few years was raised as an Adams, as can be found in the 1880 census. At that time, three generations were living in the family homestead, my great great grandmother, my GGF and GGM with their two children, and Aunt Carrie and little Lester.
Above is a picture of the three boys when they were in their late teens or early 20s. I think it was taken about 1895-1898. The one on the left is Lester, with his cousins Elmer, and Kirt, who is my grandfather. They are on the farm in Peru before it burned about 1900. By this time, Aunt Carrie had married and Lester took his stepfather's last name.
He went on to lead a good life, as a husband and father, a merchant, and a town manager. I have a letter that my grandfather wrote to my dad during WW2, telling dad that cousin Lester had died. My grandfather said he had lived a Christian life, which I take to mean that he was a wonderful person, kind and honest, and someone my grandfather was proud to have in the family.
I knew Lester's daughter in her later years, and because my family enjoyed working on genealogy, my aunt told me never to talk about genealogy around her. There was this distant oops that mustn't be spoken of.
Lester has grandchildren and great grandchildren, and maybe they know this, and maybe they don't. No one in my generation on my side of the family knows who Lester's father was. We have a story, that may be fantasy, about a minister. Aunt Carrie was very bright, and he would have been her intellectual equal. We know Aunt Carrie made a train trip to see her sister in Iowa, and when she came back, she was pregnant. The baby was named Dudley Lester Adams. Aunt Carrie would have known who Robert Dudley, Earl of Leicester was in history. There is a clue to his paternity there, but I can't unravel it. Maybe DNA will someday.