That's pizza al taglio.
We called it sheet pizza as opposed to round shaped pizza. It was all Sicilian style but we did not call it that as Sicilian is the only kind of pizza we ever saw in the pizza shops. You got a sheet pizza if you had a lot of people and needed a BIG pizza.
https://en.wikipedia.org/wiki/Sicilian_pizza"In the United States, "Sicilian pizza" is used to describe a typically square variety of cheese pizza with dough over an inch thick, a crunchy base, and an airy interior. It is derived from the sfinciuni and was introduced in the United States by the first Italian (Sicilian) immigrants. Sicilian-style pizza is popular in Italian-American enclaves throughout the northeastern United States, including Massachusetts, Rhode Island, Michigan, Connecticut, New York, and New Jersey."