There are two major facts that led to pizza becoming THE dish to be ordered via telephone and delivered to the home.
After World War II, the telephone networks saw rapid expansion, and more efficient telephone sets, such as the model 500 telephone in the United States, were developed that permitted larger local networks centered around central offices. A breakthrough new technology was the introduction of Touch-Tone signaling using push-button telephones by the American Telephone & Telegraph Company (AT&T) in 1963.
While at the same time an estimated 600,000 Italians arrived in America in the decades following the war. As was, and still is a regular occurrence for immigrants, a large number of them ended up working in the food industry, often opening inexpensive restaurants serving Italian food.
Which was a fortuitous choice, because not long before, the American veterans of campaigns in Italy returned home, with a taste for Italian food already developed.
As it were, the first inexpensive and proliferated telephones, and the influx of cheap, tasty Italian food was a match made in heaven. The startup family restaurants ran by Italian immigrants could not compete with the established food industry, could not afford rent on big floors required for a major restaurant to sit enough clients to support themselves, but they could deliver the food to the homes of their patrons; both to other Italian-Americans, as well as a growing number of other ethnicities as well.
This, in turn, worked well with an increased demand for ready-made food, required due to an increasing percentage of women joining the workforce and thus unable to cook at home.
Now, this part was easy to answer, but why PIZZA of all the possible Italian dishes? There is no definite answer, as usual for matters of taste and preference.
Pizza, at its most basic, is simply a flat-bread with cheap toppings. Flatbread is by far the most popular dish in the world, eaten in various forms by virtually every culture known to historians, but especially popular among Mediterranean cultures. It is very cheap, calories-dense, does not spoil easily, easy to transport, share and cut, and can be eaten with anything.
We know it as pita, naan, flatcakes, or chatapouri, but it’s pizza that manages to be both cheap, and “luxurious” looking enough to be sellable to strangers who might be not familiar with it. It requires no rare ingredients, the procedure of making it is easy, and about the only non-standard piece of equipment needed is a wide oven. It is also easily stackable and transportable, which was a nontrivial matter to delivery men in 1950s automobiles and bike delivery.
2. Candeloro, Dominic. “Suburban Italians” in; Ethnic Chicago
3. Fischer, Claude America calling: A social history of the telephone
4. Liz Barrett , Pizza, A Slice of American History”
5. Turim, Gayle. “A Slice of History: Pizza Through the Ages