Since its establishment, Sigma Gamma Rho Sorority, Inc. has promoted unity among women. For many years, numerous alumnae chapters collaborated with individuals who were not members of Greek-lettered organizations. These women were organized into auxiliaries that held various names until 1954. The sorority formally approved the organized affiliate group and designated Philo, the Greek word for “Friend” the affiliate’s official name. In 1980, the Philos were established on a national level and has since grown to encompass hundreds of women organized at regional and local levels. The Philos have dedicated countless hours of community service and contributed thousands of dollars to Sigma Gamma Rho’s mission of enhancing the quality of life within every community.
On March 27, 1990, the Eta Delta Sigma Philo Affiliate was charted by the following women: 
Mrs. Velma Smoot, mother of Charter member Donna Smoot Walters; Mrs. Marie Thomas, mother of Charter member Gail Thomas; and Ms. Terry Enlow, cousin of Charter member Yolanda Lewis. Charter member Gail Thomas served as the advisor, and Philo Velma Smoot was elected as the first Philo President.