His parents were both born in the USA: This is them in 1900 living in Los Angeles with Crippens natural son, the cenus form asked for the Country of birth of each person, Myron Augustus Crippen put New York for his parents and his wife put Wales for her fathers birth and Pensylvania for her mother's birth. Interestingly, the son hawley otto, who was left with the grandparents, gives his father's birthplace as Michigan but his mother's birthplace as Ireland, she was called Charlotte and died in 1892 but I;ve not found her maiden name yet.
1900 census Los Angeles:
Myron A Crippen
Home in 1900: Pasadena Precinct 5, Los Angeles, California
[Pasadena, Los Angeles, California]
Age: 65
Birth Date: Apr 1835
Birthplace: New York
Race: White
Gender: Male
Relationship to head-of-house: Head
Father's Birthplace: New York
Mother's Birthplace: New York
Spouse's name: Ardessa Crippen
Marriage Year: 1856
Marital Status: Married
Years Married: 44
Occupation: View on Image
Household Members:
Name Age
Myron A Crippen 65
Ardessa Crippen 64
Hawley O Crippen 10
Source Citation: Year: 1900; Census Place: Pasadena Precinct 5, Los Angeles, California; Roll: T623_91; Page: 3B; Enumeration District: 117.