Pizza was brought to the United States with Italian immigrants in the late nineteenth century; and first appeared in areas where Italian immigrants concentrated. The country's first pizzeria (place that focuses in pizza), Lombardi's, opened in 1905. Veterans returning from World War II's Italian Campaign were a ready market for pizza. Since then, pizza consumption has increased in the U.S. Pizza chains such as Domino's, Pizza Hut, and Papa John's, have outlets all over the nation. Thirteen percent of the U.S. population eats pizza on any given day. 