Sort and rinse black beans. Cover with water and let soak overnight.
Place ham bone in slow cooker.
Drain beans and add to slow cooker.
Add onion, green pepper, garlic, water, salt, pepper, chili powder and cumin.
Stir to combine.
Cook on high 7-8 hours.
Remove the ham bone from pot.
Remove half of soup and place in a blender. Blend until smooth. Return to the slow cooker.
Stir in vinegar.
Serve with diced raw onion and sour cream, if desired.