Oh, heritage. Fun.
My mother is adopted and although we have done some research into her birth family, I know nothing about their genetics/heritage.
My father is not adopted although his mother is adopted. Her formerly long-lost sister (adopted by a family on the other side of the country) was inspired by their reunion to do some very heavy research, and traced their birth family all the way back to the Black Douglas clan of ~15th century Scotland.
My father's father was not adopted. His great-something grandparents came to America from Germany, I'd assume in the mid-19th century, and (if I remember correctly) more of his ancestors (maybe even his parents or grandparents) came from Germany in the early 20th century to escape a World War.
1/4 German, 1/4 Scottish, 1/2 unknown.