I came across an awesome link. It focuses on the evolution of the Manhattan in concerns to its urban fabric. I hope that the creator keeps this running and updated. You can play around with several different ways to view the city, and it gives a very concise illustration of how it changed over the twentieth century. Check it out. http://skyscraper.org/timeformations/intro.html

Above: Illustrates what areas of the city has been effected by urban renewal.

Above: Shows the Dutch Settlement that started it all, "New Amsterdam".

Above: Shows both New Amsterdam and the 1811 grid plan.

Below: Also several interesting aspects of the city are illustrated like farms and green space.