New York, for one, is next to a port, making it a stop for immigrants since the 1800's. This means that their is a lot of people coming through it, and even just moving to the large city. With the amount of people that traffic through it, it leads to new businesses starting and centering around it. This process has been growing since immigrants first came, and NY has expanded so much that now it is a bustling city, all because it is next to a port! XD Hope this helps!
