Peggy Dow was born in Columbia, Mississippi, USA on March 18, 1928, as Peggy Josephine Varnadow. She married Walter Helmerich III in 1951 and had 5 children with him. Among her most important works are Harvey (1950), Bright Victory (1951), I Want You (1951), and You Never Can Tell (1951). She studied at Louisiana State and Northwestern State University and participated in many theater performances on the university stage, then worked for a short period in 1949 on the radio and television. She signed a contract with Universal, and her first film was Undertow (1949), followed by Woman in Hiding (1950). She gained fame after her performance as a nurse in the film Harvey (1950). She retired in Tulsa, Oklahoma, to support her husband in his oil business and had five children and 12 grandchildren. She became involved in social work in Tulsa and received an honorary degree from the University of Oklahoma for her assistance in improving education, health care, and culture in Tulsa.