When was New York City a real city?
I'm not sure what the term "a real city" is supposed to mean.
Real, as in, not imaginary or fictional? Or "real," as in, it fits
the official definition of a city, in terms of population, land
size, economy, government, etc.?
What you meant by "real" is not terribly important, however,
since New York City IS a real city, in any and every sense of the
word.