Fry bacon in skillet on stove top over medium heat until crispy.
Remove bacon to paper towel-lined plate to drain; once cool enough to touch, crumble bacon and set aside.
Add chopped onion to bacon grease in skillet and saute’ a few minutes.
Add garlic and continue to saute’ until onions are translucent and lightly browned.
Add crumbled bacon to onions and garlic and stir to combine; remove from heat.
Add diced tomatoes, tomato sauce, Italian seasoning, balsamic vinegar, crushed red pepper, wine and onion/garlic/bacon mixture to 4-quart slow cooker and stir to combine.
Taste and add salt, if necessary.
Cover and turn slow cooker on high and simmer for 4 hours.
Serve over favorite pasta and sprinkle with fresh parsley (optional).