Big Apple
Although the history of "Big Apple " was once thought a mystery, a clearer picture of the term's history has emerged due to the work of amateur etymologist Barry Popik, and Gerald Cohen of Missouri University of Science and Technology. A number of false theories had previously existed, including a claim that the term derived from a woman named Eve who ran a brothel in the city. This was subsequently exposed as a hoax.
New York City
New York became the most populous urbanized area in the world in the early 1920s, overtaking London. The metropolitan area surpassed the 10 million mark in the early 1930s, becoming the first megacity in human history. The difficult years of the Great Depression saw the election of reformer Fiorello La Guardia as mayor and the fall of Tammany Hall after eighty years of political dominance.