Caddell served in World War II. In 1947, while working at the delicatessen, he spotted Catherine Williams from the window. He tracked her down later and began a courtship that ended with a June 1948 wedding. She immediately joined in with the family businesses, running the Homewood Car Wash with her husband. He purchased Homewood's Little Southerner supper club and renamed it Jack Caddell's.
Later he bought the Pig Trail Inn barbecue restaurant and teen hangout founded in 1953 by W. D. Powell. In 1960 Caddell researched the operations of the newly-franchised McDonald's restaurant chain. He created Jack's Hamburgers based on that model, with the first drive-in location opening in downtown Homewood on November 21 of that year. At some point he moved the original Jack's into the Pig Trail Inn building at 2831 19th Street South. The chain grew to 17 locations before he sold it in 1969 to Florida Capital.
Caddell suffered from heart problems in 1990, and died the following March following a heart attack. He was survived by his wife and two children, Jack Jr and Elizabeth. Catherine sold the successful restaurant to Eli Stevens in 1992.
- "Santa and Uncle Cliff [sic] to help open Jack's Hamburger Drive-in" (November 23, 1960) Shades Valley Sun - via Birmingham Rewound
- Nance, Rahkia (December 27, 2009) "Restauranteur Catherine Caddell dies." The Birmingham News
- Hollis, Tim (November 12, 2010) "Back to Jack's." Birmingham magazine