Robert Cargill was born 15 June 1929 in Cushing, Oklahoma, United States to Conner W. Cargill (1908-2004) and Bonnie V. Davenport (1912-1965) and died 4 April 2015 Fort Worth, Texas, United States of unspecified causes.
Children
| Name | Birth | Death | Joined with |
| Sara Cargill (1957) | 17 July 1957 Fort Worth, Texas, United States | John Lee (1955) | |
Siblings
| Name | Birth | Death | Joined with |
| Robert Lee Cargill (1929-2015) | 15 June 1929 Cushing, Oklahoma, United States | 4 April 2015 Fort Worth, Texas, United States | Sara Lou Young (1928-2020) |