A native of Avondale Estates, Georgia, Bob was born October 11, 1933, the oldest of five children of Charles and Evelyn (Parker) Caldwell. After graduating from Avondale High School in 1950, Bob joined his father running the family business, a grocery and feed store and pillar of the Avondale Estates community. He was handy from an early age, with all things mechanical coming naturally to him so he could frequently be found helping family, friends, and community members with projects. Bob was drafted into the armed forces in 1956, upon which he was placed in the United States Navy. He served from 1956 to 1962 during which he completed two Mediterranean deployments spending time on the USS Miller, a destroyer. After his active duty, Bob continued to serve in the United States Naval Reserves for another twenty-nine years.

Bob was a pillar in the Avondale Estates and Tucker communities during his life. Bob purchased his Western Auto store in 1971 in Avondale Estates, a fixture of the local community. In 1976, Bob purchased the Tucker Western Auto store and moved the operation to the Tucker location until 1984. Thereafter, he was involved in construction and courier businesses. Bob was a lifelong member of the Baptist Church, serving as a deacon and multiple tenures as the chairman of the deacons. As of late, he was a member of the First Baptist Church of Stone Mountain. He joined the Tucker Masonic Lodge No. 42 in 1980, serving as lodge Master in 1989, and was also a founding member of the Decatur Optimist Breakfast Club, a chapter of Optimist International. Bob enjoyed serving the community whether volunteering through the church and charitable organizations or serving as a poll worker during elections.