Why is NYC population so big?
Why is NYC population so big? First, the port of New York came to dominate American shipping and immigration completely. Second, New York exploded as a manufacturing town, as industries such as sugar, publishing, and most importantly the garment trade clustered around the port.
What if all humans lived in one city?
[General] If the Earth's population lived in one city how would that look? It's a statement fact: if the entire world's population lived in a city with the density of New York it would take up a space roughly as large as the state of Texas.