Map of How Manhattan's Grid Grew, from NY Times (get it while it's free) ...
The grid certified by the city's street commissioners on March 22, 1811, spurred development by establishing seven miles of regular, predictable street access. It also laid the groundwork for nearly 2,000 acres of landfill that would be added to the island over the next two centuries. The commissioners concluded that New York "is to be composed principally of the habitations of men, and that straight-sided and right-angled houses are the most cheap to build and the most convenient to live in."
