Image source: http://maps.nyc.gov/

Woven across Manhattan Island is a vast tapestry of street and block that has been so successful in organizing the forces of urban development, it's often hard to see the simple pattern that exists below the city's skyscraper forest. Manhattan's street grid is potentially the most powerful city building tool ever created. It has forced all new growth to integrate itself into the rest of the city, linking new into the old through interlocking blocks that have formed a geometrically simple yet complex urban structure. A structure that has fueled the island's dense, mixed use, walkable, and transit friendly form that so many other cities try yet fail to achieve today.

What has been lost in the ignorance and rejection of the core principles of the Manhattan grid, to the detriment of most cities in the western world, is the ability to establish the physical pattern that new growth and development will take in order to integrate itself into a connected urban whole. Even after years of study and research; after the late great Jane Jacobs brought to light the vitality of interconnectedness and neighbourhood mish-mash; after all the ideological experiments for real urbanism have remained sterile; the Manhattan street grid has remained forgotten.

Known as the Commissioners Plan, the grid plan was adopted in 1811 and established the block pattern from 14^th to 155^th Street, some 11 miles away. Thick veins that would become the city's future avenues ran parallel to the Hudson and East Rivers, and connected new Manhattan with the jumbled roads of old downtown.  Streets would bisect the avenues every 200 feet, forming shallow blocks. The grid plan was laid down atop hill and plain, forest and farm, cut through houses and paved over rivers.

Yet even as late as the 1890?s, many portions of the island remained under construction. Unfinished neighborhoods were still being produced along unfinished streets; slowly and piece by piece. Manhattan's population at this time was still expanding northwards along with the all important subways lines and avenues which fed commuters downtown. But the grid prevailed, nearly one hundred years after it was originally conceived, and continued to as the blocks grew fuller and denser.

These blocks were created as new streets were layed down, one after the other; orderly New York growing in orderly fashion according to that all-encompassing grid plan. Looking at a map with the numbered street names and seeing the rigidity of square and rectangle would give the illusion of dull and banal expanses of city. The whimsies of London's ancient curves relinquished. How can endless straight lines of a presupposed repeating pattern allow the diversity of uses and needs a city requires in order to function and prosper?

It was the spaces within the grid, carved out in piecemeal fashion as speculators developed their properties over time. While the Manhattan's grid was imposed across the island at a city-wide scale and from a top-down perspective, individual parcels took shape and developed themselves over time according to their individual values and needs. This hyper-local building pattern within the block gave Manhattan small scale variety within its larger block context. Even though each block was the same shape and size as the next, within those blocks there could be different building types, styles, uses and ages. Jane Jacobs's described these variables as some of the key ingredients that foster a neighbourhood's diversity and subsequently improve its long-term economic health.

This micro diversity was however still predicated on the comprehensive and unwavering implementation of the grid pattern. The grid's macro-scale immediately connected newly developed areas into the existing urban fabric without interruption or segregation. There was an equal playing field for the speculators who sought to develop their properties for maximum return, with each block as connected to the rest of the city as the next. As a result, there was certainty – certainty that there would be a new urban areas created beyond your individual parcels that would feed the forces of agglomeration.

Blocks were created and filled in as needed with brownstones, apartment buildings, offices, churches, parks, schools, factories, bakeries, butchers, cafes, and every other store, shop, home, and workplace they needed. The grid was there for their use. The grid was their building block, but did not tell them what was needed inside. Market forces and the needs of the locals dictated that. Today, the vibrancy of these blocks remains, with the diversity of uses spilling out of every gridded street corner from Union Square to Washington Heights.

Upper Manhattan in 1897. Blocks were still being created and filled in as the city grew northward. Image copyright Museum of the City of New York.

Of course, the success and phenomenal growth of Manhattan was fueled by so many other factors; the grid alone isn't what made Manhattan one of the largest and densest urban areas in the world. The point is that the grid organized this growth, gave it a structure from which it could continue to grow. Fully connecting new blocks into the older ones around it allowed for catalytic interactions; growth feeding growth feeding more growth. Strength in numbers; strength in connectivity.

And Manhattan wasn't the only city to lay out a large-scale grid plan, although it was certainly the largest. San Francisco, Chicago, and Washington D.C. too have thrived through their own comprehensive grid plan variations. Thousands of more places across North America, booming resource towns and newly-connected railroad hubs, developed initially on some sort of grid-like pattern that would allow for ease of subdivision and the benefits of interconnectivity. Downtown, often the most beloved place for residents of Anywhere, USA, grew this way. The older neighbourhoods around them, the original suburbs, grew this way.

Cities stopped growing this way, of course. Fueled in large part by land use separation and zoning codes, urban growth morphed into exclusion and disconnection. Residential neighbourhoods were designed from scratch, disassociated from the original nearby streets and blocks. Rather than plugging themselves into the city, they ignored it. Insularity prevailed. Combined with a removal of industry from downtown and with shopping areas relegated to plazas or malls, the interconnected city unwound itself. Blocks now served to connect only to the other blocks within an individual neighbourhood made up of exactly the same building types, ages and uses, surrounded by wide arterial roads that no longer acted as a main street but merely as dividing line. A comprehensive vision for how the city should grow physically remained only in the form of the zoning plan; colored blobs giving unpredictable reign over the countryside's new road network. The plan of streets was left ultimately to the individual developer, although city planners and transportation engineers at this time were more than happy to encourage the disconnect as well. The modern automobile life had no need for urban connection, so why not disperse and separate?

Most examples of modern city building continue to ignore and in many cases reject the grid, or at the very least the important principles of a forward-thinking, unwavering network of interconnected public streets that form a successfully integrated block structure. There are however efforts to re-associate ourselves with the grid, of reinvesting in its positive development power once more.

Paul Knight is an architect and city planner based out of Providence, Rhode Island. He is one of the forces behind a back to the future approach that focuses on harnessing the connective growing power of the city grid. Knight and his counterparts have studied variations of street grids across the United States, and are leading an effort to get cities back on board with 'Master Street Plans'. The goal is to refocus urbanism discussions away from land use and toward land subdivision.

"Development of land today is unwalkable, and it's very difficult to mix together different building types," Knight says, "the disconnected network of streets inhibits a city's development and intensification over time."

Instead of worrying about what types of uses emerge in any particular neighbourhood, Knight and his colleagues want city planners to focus on the street network, so that new growth can react in similar ways as in Manhattan. His proposal to undertake this, the Master Street Plan, is itself enshrined in the same federal legislation that allows cities and regions to implement zoning codes.

"Time will always bring changes in land use, yet streets and blocks will serve as a permanent organizer of city space," Knight notes. "Blocks and streets will exist for an extremely long time, and cities should be actively planning to make sure they are walkable and support the kind of urbanism they want to create"

While Knight and his team continue to advocate for a return to the square and rectangle, negative attitudes towards the grid have a long history. There was much hate for the Manhattan plan as it continued to develop in the late 1800s. With the City Beautiful movement in full swing at the end of the 19th century, places like Paris carved grand diagonals through their urban fabric to create landmark vistas. Others preferred 'natural' curvilinear streets that ebbed and flowed, considering the grid too mechanical and standardized. But these criticisms ignored what flourished inside the gridded block; buildings and people connected to another block of buildings and people, shops and businesses, homes and schools, butchers and bakers. The complexity of activity inside was enabled through their integration with everything surrounding them. These blocks enabled the ability to change and adapt to the climate and conditions of the economy.  Able to grow up when need be; the simple city block eventually supporting the forces of intensification that would lead to their skyscraperization.

Many today still may decry the grid solution as anti-environment, or at odds with the efforts of trying to 'naturalize' city-building. The recent Landscape Urbanism movement would almost certainly view the grid pattern as discordant with their own arguments for development that is respective of patterns and processes found in the nature.

Yet the grid as an urban organizational structure counter-intuitively exists as a natural extension of the very essence of our humanity. Farming is evidence of this, with fields tilled and seeds planted, row upon row on fertile grounds that most certainly never existed in such orderly conditions, or never would under 'natural' process without the divine intervention of human ingenuity. Houses themselves, the hearth and its warming comforts of family and familiarity, are incongruent with our historical necessity of tree and cave dwelling, but again offer an expression of the humanity of order.

The grid and the all encompassing plan for a city's future streets better defines urban limits, whereas the freewheeling creation of roads, blocks, and parcels in a system that doesn't impose a top-down road order obscures a city's edge. The grid corrals and keeps the city in check by ensuring new places are linked into existing parts of the block system. The grid compresses urban uses into a continuous area which allows the countryside and the natural environment to continue unobstructed and within close proximity to the city itself. In this way the grid acts as an aid to the natural environment by keeping the city away from it, rather than trying to overlay a sort of half-urban, half natural man made system of suburbia overtop of the peripheral landscape. And the grid can define edges around the precious parks needed within the city itself. Central Park offers perhaps the world's most stunning and successful reminder of this; its aesthetic and recreational beauty made only more beautiful by the rigid urbanism that surrounds it.

Jane Jacobs reminds us that cities are problems of organized complexity. The grid organizes from the top-down, allowing the diversity of self-organization to take place from the bottom-up within the grid. Image copyright Museum of the City of New York.

The process of presupposing streets and blocks in gridded formation across new areas for urban growth organizes the complexities of a city together. The grid is a magnet, pulling discordant city parts into a meaningful alignment that allows for the luxuries of modernity to take place within a functioning system of interconnected order.

Messy and tangled, interwoven and jumbled; Jane Jacobs herself understood the difficulty of rationalizing how to plan for and foster the diversity of elements that make up a great city.

The key is that when given the right lattice to build upon, forces beyond any planners or architects control can take over. The elements will build themselves in, connect to one another, grow over time, and evolve to meet their needs. Manhattan's grid remains today the best example of this simple yet misunderstood principle at the core of successful city building. All wrapped up in the integration of a basic rectangular shape is the ability to form neighbourhoods, to mix building types and uses together, to bridge the gap between new places and old, to allow for people to walk from home to work and back, and to create a city percolating with the full energies and abilities of the people who live and prosper within it.

Cities continue to grow, but not without the feeling of something missing, especially along the edge where new growth is happening. We may have gone too far in the wrong direction already, wholly disconnected with no hope of weaving it all back together. Still, we're all trying, and we have been for a long time. Here's to hoping that maybe one day we can remember how we built Manhattan.