After graduating from
Duchesne College, Cronin began working as a bacteriologist for C. A. Swanson and Sons in 1949 or 1950. The challenge of this task was figuring out how to heat several different frozen foods simultaneously in a single package while maintaining optimal taste and texture and eliminating food-borne bacterial growth. She also developed Swanson’s first fried chicken TV dinner, which she said in a 1989 interview was the biggest challenge of her time with C. A. Swanson and sons. The book included over 500 recipes focused on American cuisine from traditional foods dating back to the Colonial period to ethnic recipes that had become part of American culture. Each recipe also contained a short history and variations. Lorrie Gutman of the
Tallahassee-Democrat stated it was "one of the most interesting recipe books I've ever read". Cronin retired from Campbell's Soup Company in 1993 but worked as a consultant to Campbell's into her 60s. == Personal life ==