Many parts of NYC depopulated heavily during suburban flight, in particular Manhattan - the regional population has always trended up but many people left for the newly developed suburbs following the war.<p>Manhattan&#x27;s population for example peaked at 2.2m between 1910-1920 and still has never been that high since. Current estimates are around 1.6m.<p>Population density in Manhattan has decreased dramatically, largely owing to suburban flight and an increased demand for quality of life - it was 21 people per 5,000 sq ft in 1910[1], it is 12 people now.<p>One funny thing about all of this is that the old brick buildings that are such prized real estate nowadays used to be low-rent tenements, considered blights on the city, and where a million dollar bachelor pad now sits multiple families used to fit in the same space.<p>The pattern extends to other parts of the city also - Brooklyn peaked at 2.7m between 1940-1950 and rapidly depopulated afterwards, even now the borough only has ~2.5m people.<p>The depopulation is a large part of NYC&#x27;s reputation in the 60s, 70s, and 80s as a dangerous place - abandoned buildings and depopulated neighborhoods contributed to crime and general decay, though of course cheap rent also contributed to a dramatic surge of artistic achievement.<p>tl;dr: NYC depopulated heavily after 1950, and didn&#x27;t really start recovering until the 1990s, and even then NYC&#x27;s population didn&#x27;t start growing rapidly until the early 2000s when the combination of shifting preference towards urban lifestyles and lowering crime made a large influx of population possible.<p>The resurgence of American cities is, in the grand scheme of things, an <i>extremely</i> recent phenomenon.<p>[1] <a href="http:&#x2F;&#x2F;www.nytimes.com&#x2F;interactive&#x2F;2012&#x2F;03&#x2F;01&#x2F;realestate&#x2F;manhattans-population-density-past-and-present.html?_r=0" rel="nofollow">http:&#x2F;&#x2F;www.nytimes.com&#x2F;interactive&#x2F;2012&#x2F;03&#x2F;01&#x2F;realestate&#x2F;man...</a>