Reilly was born Dorcas Lillian Bates in Woodbury, New Jersey on July 22, 1926.[2][3] She grew up in Glassboro and later in Camden.[2] Reilly attended Camden High School, along with her future husband, Thomas H. Reilly.[2] Dorcas Reilly went on to attend Drexel University, where she was a member of Alpha Sigma Alpha and earned a degree in home economics in 1947.[4][5][6] She was one of the first members of her family to go to college.[3]
Reilly started working at the Campbell's Test Kitchen in 1949.[4] She was one of the first full time employees in the department.[7] Reilly went on to become the supervisor in the home economics department.[8] She also worked as a recipe developer.[9] During her time at the test kitchen, she created hundreds of different recipes, including Campbell's tomato soup meatloaf, a tuna-noodle casserole, types of porcupine meatballs, and the Sloppy Joe "souperburger."[2][10][7] She is best known for her creation of the green bean casserole.[2]
In 1959, she married Thomas H. Reilly.[2] Dorcas Reilly left the Campbell's Test Kitchen briefly to raise her children in 1961.[3] She returned later to work as the manager of the Test Kitchen.[3] During her time back at Campell's she was cited by the Courier-Post as an expert in "cooking and entertaining."[11] Reilly retired in 1988.[3] In 2002, Reilly and Campbell's donated her recipe for green bean casserole to the National Inventors Hall of Fame.[10]
She was a member of the Order of the Eastern Star and the Daughters of the American Revolution.[6]
Reilly died on October 15, 2018, in Camden, New Jersey from Alzheimer's disease.[2][7][12]