Dorcas began her career at Campbell Soup Company, working in their Home Economics Department. This department was responsible for developing recipes and promoting Campbell's products to consumers.

Spent time creating and testing numerous recipes using Campbell's soups and other products, contributing to the company's marketing efforts.

Dorcas Reilly, as part of a team of home economists, created the Green Bean Casserole recipe for an Associated Press feature. It was a quick and easy side dish using canned green beans, cream of mushroom soup, and French-fried onions.

The Green Bean Casserole recipe quickly gained popularity, becoming a staple dish at Thanksgiving and other holiday meals. Campbell's heavily promoted the recipe, further solidifying its place in American cuisine.

She continued to work at Campbell's, developing and testing other recipes, contributing to cookbooks, and engaging in consumer outreach. While the Green Bean Casserole was her most famous creation, she worked on many other projects.

After a long and successful career, Dorcas Reilly retired from the Campbell Soup Company.