Bean Casserole

Ingredients

• 2 lbs lean ground beef
• 2 cups onions, chopped
• 1 cup celery, chopped
• 1 (10 3/4 ounce) can cream of tomato soup, undiluted
• 1 (6 ounce) can tomato paste
• 12 cup ketchup
• 1 (16 ounce) can green beans, drained
• 1 (17 ounce) can lima beans, drained
• 1 (15 1/2 ounce) can wax beans, drained
• 1 (16 ounce) can red kidney beans, undrained
• 1 (16 ounce) can pork and beans, undrained
• 12 cup brown sugar, packed
• 2 tablespoons prepared mustard
• 14 cup pure maple syrup (optional)