Meat-Lover's Slow Cooker Spaghetti Sauce

I started making this sauce in the 60's..LOVE IT !!! Mz. Bizkit

2 tbsp. olive oil
2 small onions, chopped
1/4 lb. bulk Italian sausage
1 lb. ground beef
1 tsp. dried Italian herb seasoning
1 tsp. garlic powder
1/2 tsp. dried marjoram
1 can (29 oz.) tomato sauce
1 can (6 oz.) tomato paste
1 can (14.5 oz.) Italian-style diced tomatoes
1 can (14.5 oz.) Italian-style stewed tomatoes
1/4 tsp.  dried basil
1/2 tsp. dried oregano
2 tsp. garlic powder
1 tbsp. white sugar 
      Heat olive oil in a skillet over medium heat; cook, stir onions and Italian sausage until sausage is browned, about 10 minutes.  Transfer sausage and onions to a crockpot.  In same skillet, cook and stir ground beef, Italian seasoning, 1 tsp. garlic powder and marjoram, breaking meat up as it cooks, until meat is browned, about 10 minutes.  Transfer ground beef into crockpot.  Stir in tomato sauce, tomato paste, diced tomatoes, stewed tomatoes, thyme, basil, oregano, and 2 tsp. garlic powder.  Set cooker on Low, cook sauce 8 hours.  About 15 minutes before serving, stir in sugar.  Serve hot.