Cook bacon in skillet/frying pan until crisp. Once cooked, remove from grease and crumble. Sautee onion in bacon grease until transparent. Remove from the grease and set aside. Brown ground meat in grease and drain well. Mix together the ketchup, brown sugar, vinegar, and mustard. Add the beans and stir gemtly. Add bacon, onion and ground meat. Stir just to blend. Cook in a bean pot for aproximately 1 hour at 350-375, or in a crockpot overnight on low.