Add potatoes to a large pot and cover with cold water. Bring to a boil and cook until potatoes are tender, about 10-15 minutes. Drain and set aside to cool.
In a small bowl, whisk together mayonnaise, sour cream, vinegar, sugar, salt, and pepper. Set aside.
In a large bowl, combine cooled potatoes, red onion, celery, bell pepper, and parsley. Pour the dressing over the potato mixture and stir until evenly coated.
Cover and refrigerate for at least 2 hours before serving.
Interesting Facts
Potato salad is a popular dish in Germany and the United States.
The potato is native to the Andes Mountains in South America and was first cultivated by the Incas.
Potatoes are a good source of vitamin C, potassium, and dietary fiber.