I think it was a combination of these preliminary, almost default moves toward the grid, a sense of its practicality, of its easy-to-implement nature, of its enabling of real estate development, that tipped them in that way,” says Ballon. “My hunch is they didn’t seriously consider any other strategy.
How Manhattan became Manhattan is most interesting when compared to the identity of the city, and how different style elements, say European style boulevards or roundabouts, might have flavored Manhattan instead.
A Visual History of Manhattan’s Grid - Design - The Atlantic Cities
Source: theatlanticcities.com