You could say that pizza connects the world, since it is beloved in every county, but it really took the connected world to create the pizza.
For one, tomatoes are actually a New World fruit (and yes, tomatoes are fruit), native to South America. Early European explorers brought tomatoes back to Europe, including Italy, where they became a mainstay ingredient in many dishes, such as pizza.

Meanwhile, flatbreads topped with various ingredients have been around for centuries. Flatbread is easy to prepare and quick to cook. In the 18th century, Naples was a boom town with a swelling population to support trade. Dock workers and other low-wage laborers needed quick and cheap food. Thus, pizza was born, initially as a street food.
Vendors could cook up large flatbreads topped with various things, including tomatoes and cheese. When someone came to buy a slice, the vendor could simply cut off as much as the person could afford.
Initially, pizza was scorned by most wealthy people, who preferred more complicated (and expensive) dishes. Eating simple flatbreads was seen as something for the poor. Many Italian cookbooks from the 19th century skipped over pizza.
On a visit to Naples in 1889, King Umberto I and Queen Margherita, the rulers of unified Italy, decided to sample some of the local fare. Queen Margherita ordered a flatbread recipe from a local cook. He came up with a cheese, basil, and tomato mixture on flatbread, allegedly in honor of unified Italy’s white, green, and red flag. Now called the Margherita pizza, this dish paved the way for modern pizza. Some say this also constituted the first pizza delivery since the queen didn’t actually go on the street — The cook delivered it.
Each year, Americans alone consume more than three billion pizzas. Every day, Americans eat more than a hundred acres of pizza.