If you think Manhattan is bursting at the seams now, good thing you (presumably) did not live in the borough in the 1910s when its population density was inconceivably higher. Newly visualized research by NYU urban scholars Solly Angel and Patrick Lamson-Hall, shared by CityLab, depicts the borough's waxing and waning population between 1800 and today in all of two minutes. Angel and Lamson-Hall used census data, historical maps, and aerial photographs to track density by neighborhood, ultimately depicting that the island was just awash with humans on top of humans when its density peaked in 1910 (after, even, the Jacob Riis years), and was drained pretty substantially through the 20th century until the 80s when people decided it was a good idea to live in this town again.
While the visual only represents the rise and fall of population density, Angel and Lamson-Hall go further to explain what's behind it,
We found that densities remained stable, at 200 persons per hectare [Ed. note: 2.47 acres], until 1840 when the growth in the built-up area could no longer keep up with rapid population growth. By 1910, average densities in Manhattan were triple those of 1840, while average densities in some neighborhoods were twice as high and more. Densities then started to decline, largely due to three public actions: the annexation of Brooklyn, Queens, the Bronx and Richmond County to Manhattan in 1898; the creation of vast new areas for urban expansion in the 1900 Topographical Bureau plan; and the building of the subway system from 1904 onwards. These actions led to the rapid decongestion of Manhattan's overcrowded neighborhoods, as lower-income workers suburbanized while still commuting to Manhattan on a nickel fare. Densities in Manhattan declined until 1980 and have risen slightly since. New York City is now expecting a significant increase in population, entailing significant densification in Manhattan and elsewhere.
The lesson here?: Be grateful, 'cause the city could be worse in many ways.
· Watch 210 Years of Manhattan Densification In 2 Minutes [CityLab]
· The Rise and Fall of Manhattan's Densities [official]