According to the 1920 census, Frank's father was born in Sweden.https://familysearch.org/pal:/MM9.1.1/MV38-VYShttps://familysearch.org/pal:/MM9.1.1/KXB2-8HKhttps://familysearch.org/pal:/MM9.1.1/XMPQ-7FS
Since Frank is Philip's brother, looking for him may lead to success finding info on the rest of the family.
The 1930 census says Frank's father was born in Norway.......
This is a big help. The marriage record for Frank Olsen and Kathleen Jordan lists Frank's parents as William Olsen and Mary C. Peterson.https://familysearch.org/pal:/MM9.1.1/FFTM-8LL