Cook:8 hrs to 10 hrs (low) or 4 to 5 hours (high) + 15 minutes (high)
In a large skillet cook ground beef, onion, sweet pepper, celery, carrot, and garlic over medium heat until meat is browned and vegetables are tender. Drain off fat. Transfer meat mixture to a 3 1/2- to 4-quart slow cooker. Stir the next eight ingredients (through cayenne pepper) into meat mixture in cooker.
Cover and cook on low 8 to 10 hours or on high 4 to 5 hours.
If using low setting, turn to high. Stir in spaghetti. Cover and cook 15 to 20 minutes more or until pasta is tender. If desired, serve with cheesy garlic bread.