I can add a little to this too, it was indeed the U.S. service men who were stationed in Italy and upon returning home were looking for a job but work was mighty scarce post WWII so many of them turned to doing something that they learned while in the service, my dad and 3 uncles opened a garage (that's a story in itself) while others did indeed remember that great Italian food "pizza" but rather than going looking for it they got busy and made it as a living. this is why a lot of the early pizzerias (since 1945) were run by vets. The problem was that no one knew where to put pizza on the daily menu, was it for lunch, or dinner? Neither, it was considered as a snack food for a good number of years with the majority of pizzas being sold after 7:00 p.m. and until the dough ran out or midnight, which ever came first. In the 60,s the big pizza chains started to come into their own and pizza began to settle in as dinner fare. Then the wholesale pizza manufacturers jumped into the pool and the marketing of frozen pizzas was a big thing. The time during the late 70's and early 80's was known as the time of the "pizza wars" with all of the large wholesale manufacturers trying to out compete the competition, it got so bad that pizzas had to be labeled as being made with tomato product (sauce) and cheese product (cheese). They couldn't be called tomato or cheese because both were heavily extended with fiber materials to reduce the cost. Toppings were absolutely scarce too, people used to buy a pizza along with onion, peppers and sausage or pepperoni to build their own pizza on the store bought frozen pizza. This was referred to as "doctoring the pizza". I helped develop the first heavily topped frozen pizza that broke the mold and made way for the quality pendulum to swing the other way and open the door to high end pizzas much as we know today. The pizza industry is unlike other segments of the food industry in that the independents are the true leaders of innovation, and then the chains jump on the idea and lastly the wholesale manufacturers jump on it too making that type or style of pizza available to the masses.
How popular is pizza? Pizza became more popular in the U.S. than our sacred hamburger by the early 90's, it is so popular that it is jokingly referred to as the great American food and this might not be too far off the mark in that the most popular types of pizza sold in the U.S. today are the "loaded" pizzas, much unlike pizzas sold any other place. As pizza has continued to evolve and tastes continue to change there has been a steady move fresh, natural, organic and combined with the demand for thinner crusts thanks to the low carb craze of a few years ago we got a lot of thin crust pizzas with a lot of toppings, but now the new direction seems to be leading us to seek out something different in pizzas, we are seeing a growing trend towards basic or natural eating styles, people want to see their food made before them, they want it to be made in a rustic/old fashion way so pizza is now beginning to come full circle and returning to its roots where it is made in a coal or wood fired oven, fresh ingredients are used, flavor and aroma are becoming important quality attributes, and less topping ingredients are becoming the rule instead of the exception. This is just a very rough thumb nail sketch of how pizzas have evolved as a mainstream food in the United States.
Tom Lehmann/The Dough Doctor