Many regional variations of pizza the United States have been developed, many bearing only a casual resemblance to the Italian original. Pizza became most popular in America after soldiers stationed in Italy returned from World War II. During the latter half of the 20th century, pizza in the United States became an iconic dish of considerable popularity. The American slang terms za and slice can also refer to pizza. The thickness of the crust depends on what the consumer prefers; both thick and thin crust are popular. Often, foods such as barbecued chicken and bacon cheeseburgers are used to create new types of pizza.