The early pizza was not the tomato-cheesy goodness that you imagine. Tomatoes arrived in Italy only in the 16th century. The pizza of the middle ages was more like focaccia, a cooked dough which usually didn’t have toppings. Although it comes from Italy, pizza could be considered an all-American food. Each year, Americans spend around $ 37 billion on the fast food dish. Pizza was mostly eaten by working class Italian immigrants, until American GIs discovered their love for pizza in Italy and spread the word when they came home. The first frozen pizza was sold in 1962, but it took a while until it tasted of anything but cardboard.