This Overnight Vegetable Salad is a timeless Southern favorite that combines crisp green peas, tender green beans, sweet white corn, crunchy celery, and fresh onion. All of it soaks overnight in a sweet, tangy dressing that brings out the best flavors in every bite. Simple to prepare ahead and perfect for gatherings, this chilled salad stays fresh for days and brightens any table, from potlucks to family suppers.