How long is a city block?

[OxyMoron]

*Originally posted by lurker b *
**In Manhattan I call streets short blocks and avenues long blocks. Lots of people I know refer to them the same way. Baron correctly stated that a mile is the equivalent of 20 short blocks. “They” also say that four long blocks are one mile, but this has never seemed quite right to me. **

Part of the reason that doesn’t “seem right” is that the “long blocks” vary in length.

Fourth (now Park), Fifth and Sixth Avenues were laid out in the 1790s. The remaining avenues were arranged in the 1811 Commissioners’ Plan, a landmark in city planning, and were closer together. From the Commissioners’ Report:

The avenues to the eastward of number one are marked A, B, C, and D. The space between the First and Second avenues is six hundred and fifty feet; from the Second to the Third avenue is six hundred and ten feet. The spaces from the Third to the Fourth, from the Fourth to the Fifth (which is the Manhattanville avenue or Middle road), and from the Fifth to the Sixth avenue, are each nine hundred and twenty feet. The spaces west of number six are each of them eight hundred feet.

Lexington (between 3rd and Park) and Madison (between Park and 5th) Avenues joined the plan as afterthoughts, once real estate developers realized that the original layout left too many midbock lots and not enough corner lots. (I believe they opened the 1830s, shortly after President Madison’s death.)

Rebecca Read Shanor’s wonderfully informative The City That Never Was (1988) includes a story about a 1910 proposal by Mayor Gaynor to insert a similar avenue between 5th and 6th. By that time, of course, the condemnation costs would have been astronomical; the proposal died with Gaynor.

For more, see this summary from Cornell.