Pizza is one of the world's most popular fast foods. It's believed that over 5 billion pizzas are sold around the world every year. In the US alone, people buy about 3 billion pizzas each year, which is about 46 slices per person! But it wasn't always as popular as it is today — in fact, it used to be looked down on, even by Italians! The modern pizza we know today started in Naples, Italy, in the 18th century. Poor people in the city needed cheap food that was easy to eat as they looked for work. Street vendors sold them pizzas with simple toppings like garlic and tomatoes. For a long time, pizza was looked down on as food for the poor, and visitors to Naples thought it was dirty and unappealing. But this changed in 1889, when Queen Margherita of Italy tried pizza and loved it. The pizza with tomatoes, mozzarella and basil was named after her, and pizza started to become a national dish in Italy. Pizza became a favorite in the US after Italian immigrants brought it with them. It became especially popular in cities like New York, and new styles like Chicago deep dish and Hawaiian were invented. And it became even more popular with the invention of frozen pizza, which let people make their own pizzas at home. Today, pizza is enjoyed around the world, with many different toppings and styles. But its basic form hasn't changed very much from all those years ago.