The Midwest ascribes to the definition of "salad" that's more heavy on the "mixed ingredients and cold" sense than the "leafy greens" sense.
Everyone quietly accepts potato salad, chicken salad, and fruit salad, but the Midwest dives into various dessert salads that involve jello, marshmallows, whipped cream, fruit and a lot of other options.

They're invariably chosen for potlucks or gatherings where everyone brings a dish, since they're a dessert where it's easy to prepare a stupendous quantity quickly, and it keeps at room temperature with good quality for quite a while.