Add all ingredients into a 6-quart crock pot then cook on low for 4 hours or until chicken breasts are cooked through. Rice should be done around the same time. Shred chicken then stir back into soup and serve (soup will thicken as it cools.)
Depending on the type of rice you use, it may not be cooked through at 4 hours. If that's the case, shred chicken then keep in the refrigerator until rice is tender, then stir into soup and let warm for 5 minutes before serving.