Check out this proposal from the 1930's on how to deal to with the booming Manhattan population:
PLUG up the Hudson river at both ends of Manhattan...divert that body of water into the Harlem river so that it might flow out into the East river and down to the Atlantic ocean...pump out the water from the area of the Hudson which has been dammed off...fill in that space...ultimately connecting the Island of Manhattan with the mainland of New Jersey...and you have the world’s eighth wonder — the reconstruction of Manhattan!
via Modern Mechanix
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