Robert Chester Caldwell was born 21 June 1913 in Pittsburg, Kansas, to William and Elizabeth Caldwell. He attended the Pittsburg Public Schools and then attended Pittsburg State University, receiving his Bachelor of Science degree in Industrial Education in 1939 and his Master of Science degree in Education in 1949. After moving to Salina, Kansas, Caldwell worked as a teacher and subsequently a principal at the segregated Dunbar Elementary School and then as a Graphic Arts instructor at Salina High School Central.

In 1969, Caldwell was elected to the Salina City Council and, in 1970, he was the first African American and first school teacher elected Mayor of Salina. Caldwell served a second term as Mayor from 1971-1972, served on the City Commission for the next two years, and was elected Mayor for a third time in 1975. In 1976, Caldwell was elected Representative of the 68th District to the Kansas State Legislature. He later served as a member of the Kansas Board of Regents from 1991-1993.

Caldwell was an active member of many organizations, including the NAACP, Kappa Alpha Psi, and the Boy Scouts. He also served on numerous committees, including the Salina Council on Human Relations, the Kansas Council on Civil Rights, and the Governor's Committee on Criminal Administration. Caldwell received many awards and commendations for his various activities, including the Kansas Wesleyan Distinguished Service Award and the University of Kansas Leadership Award in Education. In 1979 he was inducted into the Kansas Teachers Hall of Fame. Robert Caldwell died 20 October 1999.

In 1946, Caldwell married Bessie (Ellis) Caldwell. After attending public schools in Kansas City, Kansas, Bessie attended Pittsburg State University, receiving her Bachelor of Science degree in Physical Education in 1939 and her Master of Science in Education and English in 1948. After the family moved to Salina, Bessie ran the Caldwell School of Dance and taught at Marymount College, where she also served as Chair of the Physical Education Department from 1960-1975. Bessie was also very active in numerous organizations, including Alpha Kappa Alpha, the Booklovers Club, and Links, Incorporated. Bessie Caldwell died 14 April 1989. The couple had three children, Robert Ellis, Aqualyn Toy, and Teree Lynn.