I recently found out that my grandfather changed his last name about 1920. He was born to William Kirkwood and Emma Radcliffe in Ukiah, CA. Since he adopted my father in 1923 (his birth year), I had no other information about my father's biological parents. My DNA shows I have 13% European Jew. After researching my father's birthplace, I'm sure this is from my father. He was born in a hospital in San Francisco; it was common that Jewish young women who had a pregnancy, probably out of wedlock, gave birth there.