When Percy Jens Hansen was born on 5 February 1905, in California, United States, his father, Peter Hansen, was 37 and his mother, Hanne Marie Knudsen, was 33. He married Margrethe Anna Nielsen on 14 July 1938, in Oakland, Alameda, California, United States. He lived in Oakland, Alameda, California, United States for about 25 years and Alameda Judicial Township, Alameda, California, United States in 1940. He died in November 1986, at the age of 81, and was buried in Oakland, Alameda, California, United States.