I answered both questions in one paragraph:
    The reading from Delirious New York considers how New York’s grid system influenced the city’s development over time. Once the block was defined, it was rigid and almost inherent. It proved integral in all future development of the city, and it had to. It split the city into its modern “mosaic of episodes.” By splitting the city up and giving it its modern structure, the grid defined the future evolution of the city. It defined the outlines of buildings, parks and man-made geological features in Manhattan, shaping its entire physical and architectural future. It gave structure to what previously had no structure. New York City’s new grid shaped every single aspect of the city, from its creation to now.