How New York Became a Pizza Capital reports, “""When Colin Hagendorf set out to eat every pizza in New York City, he had no easy way of knowing that there are more than 1,600 restaurants officially classified as pizzerias across the five boroughs — more than every other type except Chinese and the vague catch-all category of ‘American’ eateries, according to a city health-inspection database.”

“Trying every iteration of the New York slice turned out to be more than a determined pizza hound could handle, as the Journal explains in a profile Wednesday, so Hagendorf limited his survey only to Manhattan’s slice joints. He visited 362 different pizzerias selling by the slice, excluding national chains, during his two-and-half-year mission.”

“The health-inspection database didn’t exist in 2009, when Hagendorf started his Slice Harvester project, and even now it probably understates the sheer number of pizza venues because it doesn’t tally the many non-pizzerias that happen to serve pizza. But New York City was not always the home of ubiquitous slice joints. Go back just a half-century, and the city’s culinary landscape is almost entirely devoid of pizza. Up until the late 1950s, New York pizza was largely the province of master bakers, limiting both the popularity and availability of the food. And pizza was only available by the pie; the coal-fueled ovens used to bake the pies were too hot to reheat individual slices.”