Bring first 3 ingredients to a boil in a large heavy stockpot; cover, reduce heat, and simmer 45 minutes or until chicken is tender. Drain chicken, reserving 1 quart broth in pot; skin, bone, and shred chicken, and return to pot.
Cook 1/2 cup ketchup and next 11 ingredients in a small saucepan over medium heat, stirring occasionally, 10 minutes.
Stir ketchup mixture, remaining 1 cup ketchup, tomatoes, and next 6 ingredients into chicken and broth; simmer, stirring often, 4 hours or until thickened.