Myth #9: A System of Block and Lot Divisions

By Gergely Baics and Leah Meisterlin

The New York City grid is often understood as a foundational system of land subdivision and cadastral allotment. Accordingly, the grid divides Manhattan into a highly regularized system of rectangular shaped blocks, subdivided into lots, making standard (and stackable) units of real estate available for urban development. The grid accomplishes the city’s apportionment through its collection of more frequently spaced and narrower east-west cross-streets and less frequently spaced and wider north-south avenues — each serving as partition and demarcation between the blocks with their nested lots. Indeed, conceptualizing the grid as a system of subdivided blocks highlights its underlying cadastral logic. Previous posts (#4 and #6) have addressed two myths following from this line of reasoning, specifically the extent to which block sizes determined lot sizes, and how the relentless regularity of blocks and lots contributed to rampant real estate speculation.

Less recognized though equally important is an inverse understanding of the grid, one that emphasizes its connectivity. Focusing beyond a system of block and lot divisions, our recent research discusses how the Manhattan grid provides a regular, predictable, and variable network of connections and accessibility between the city’s spaces. Conceptually, this entails more than just shifting attention from the rectangular blocks to the rectilinear streets. It involves rendering visible the grid’s underlying logic as a nodal network of highly regularized and hierarchical intersections.

Figure 1: Network of Intersections: Manhattan’s streets south of 42nd Street, 1850s

Through a sequence of three maps, Figure 1 demonstrates the logic of this inverse spatial interpretation, illustrating how the street grid embedded within and between the blocks creates a network of connectivity through its intersections. Whereas the first map represents the standard view of the street system (or block boundaries), the second visualizes the number of streets intersecting at each junction, while the third, abstracting the point further, renders visible the density of intersections across the city south of 42nd Street. Mapped in this way, block dimensions are understood as the distances that separate the nodes of this network. As a result, the regularity of the grid emerges as north-south corridors of repeated and frequent intersections. Notably, these maps exclude the grid’s variable street width from the analysis. Still, the flows of people and goods conventionally associated with the grid’s wider north-side avenues are evident, just as any indication of crosstown movement along the narrower cross-streets is almost entirely absent.

Indeed, the orderly differentiation between the north-south avenues and the east-west cross-streets derives from one key dimension: the elongated, rectangular blocks of the gridded city. It stands in stark contrast to the pre-grid pattern of multiple, dense street systems on the island’s southern portion, where the distances between intersections (block dimensions) are much shorter and more irregular. Our mapping of the network of intersections reveals two profoundly different landscapes of connectivity: one on the grid plan and one before it. Taking our argument further, insofar as connectivity is a morphological prerequisite for accessibility, reinterpreting the grid’s geometry as a nodal network of connections opens alternative lines of inquiry surrounding access to the spaces of the city.

Figure 2: A Tale of Two Manhattans? Connectivity and Access on the Street, 1850s

Figure 2 presents this analysis of accessibility across Manhattan’s streets below 42nd Street. To isolate how the spacing of intersections produces variations in accessibility, street widths are again excluded, while accessibility is conceptualized from the perspective of pedestrians. Specifically, the map measures the land area reachable within a three-minute walk from all points created on a 10-foot by 10-foot grid, across the city, and thus rendering each point that intersects the roadbed. In other words, it does not visualize the streets themselves, but rather it maps the accessibility of each street location relative to the others. It demonstrates that accessibility is primarily a function of the frequency of intersections, as more intersections in closer proximity translate into more destination options within a short walk. And while this principle holds across the city, in Manhattan’s split street geometry, the topology of its network manifests in two profoundly distinct topographies of accessibility: again, one before the grid and one on the grid plan.

Indeed, what the Manhattan grid’s dimensions did to formalize, regularize, and make consistent a topography of accessibility derived from street connectivity. It created peaks of highly accessible points along the north-south avenues, separated by valleys of limited reach at the blocks’ midpoints along the east-west cross-streets. Given all that we know of the real estate and land use development of Manhattan in the 19th century and since, this map invites inferences about the locational patterns of commerce, industry, and residence, and above all, retail. Widely understood as a system of block and lot subdivisions, the grid has long been attributed agency as having structured and fueled real estate development. Reconceptualized as a system of street connectivity, it is now suspected of having incentivized land use allocation. Toward that, how its morphology specifically shaped land uses is the topic of our next post.

Gergely Baics is Associate Professor of History and Urban Studies at Barnard College, Columbia University. Leah Meisterlin is Assistant Professor in Urban Planning at Columbia University. They are the authors of "Old Maps, New Tricks: Digital Archaeology in the 19th-Century City" and “The Grid as Algorithm for Land Use: A Reappraisal of the 1811 Manhattan Grid.”