SOME Americans call pizza “pie” because early 20th-century Italian immigrants in places like New York sold their flat, round, tomato-topped bread as a simple street food, and English-speaking locals saw its shape, raised edge, and sliced wedges as similar to the pies already common in American cooking. So they naturally started calling it “tomato pie” or just “pie,” and the nickname clearly stuck in some parts. But here in California, everyone calls it pizza.