For the first two hundred years of Manhattan history, the Collect Pond, a lovely, spring-fed reservoir that bubbled up on the border of what is now Chinatown and the Financial District, was the main water source for most city dwellers. The streets grew up organically around it, private roads bounded by a vacant, rocky, wasteland to the north, from what is now 23rd to 90th streets. These were the city-owned Common Lands, and after the revolution they were something the debt-ridden city needed to parcel out and sell fast.

By the end of the eighteenth century, the Collect Pond had turned into a quite literal cesspool, and the the city paved it over to accommodate a booming population. Five streets came together over the newly-filled pond, which still seeped though the cobblestones, and at the heart of this intersection grew a infamous slum, ruled by gangs like the Dead Rabbits and the Bowery Boys. When Charles Dickens visited in 1842, the scene shocked him:

Poverty, wretchedness, and vice….all that is loathsome…narrow ways diverging to the right and left, and reeking every where with dirt and filth.”

(That same year, he rather excitedly wrote of returning to Broadway in his diary, noting in a matter-of-factly manner the curbside intermingling of pigs, hogs, and well-dressed ladies.)

Where streets converged, so did humanity, proof positive that right angles could mean the difference between utopia and bedlam.

The Greatest Grid: The Master Plan of Manhattan 1811-2011, based on the current exhibition of the same name at the Museum of the City of New York, tells the story of the city’s right angles. The Commissioner’s Plan of 1811, the map and surveying scheme that set the blocks at 200 by 800 feet all the way up the length of the island, was an audacious gamble on growth. From 1790 to 1810, the population of New York had tripled, and the commissioners predicted that by 1860, New York would have almost the same population as Paris, then home to half a million people. (They were wrong, of course — New York would top nearly 800,000 by then.)

The grid was far from simple to achieve. “Mannahatta” translates to “island of hills,” and the rocky wasteland to the north had to be surveyed to perfection, and private roads, farms, and pastures wrestled into order by a ruthless eminent domain. This meant plenty of opportunity for graft, personified by William “Boss” Tweed, who would pocket city officials and buy up lots just as they opened city streets.

There were problems with the plan: a lack of public parks and open space, constant congestion, overbuilt lots, no vistas or urban openings for important civic buildings. The only open space the Commissioners allowed was a parade ground in the vicinity of present-day Madison Square. But the grid system allowed for these cut-throughs to happen later, in the form of Broadway, Central Park, Rockefeller Center, Columbia University, and the thousand smaller parks and plazas easily carved out of the 1811 plan.

The grid was easier to implement on the flat East side than on the hilly West. By 1860, streetcars could only travel up 8th avenue to 84th street before the terrain became impassable. Huge outcroppings of rocks, the kind that are found in the Ramble in Central Park, blocked the way for most development. Small mountains had to be blasted apart or cut through, and the hundred foot changes in elevation around Morningside Heights and Inwood has created a strange and magical neighborhood of apartments perched on peaks and valleys, still for the most part obeying the grid.

In the 1840s, at the still rural intersection of 84th and Broadway, Edgar Allan Poe rented a room at the Brennan Farm House, the likely location where he wrote “The Raven.” The farm was on a rise from the dirt Broadway road, and from his window Poe could witness nature give way to the city:

These magnificent placers are doomed. The spirit of Improvement has withered them with its acrid breath. Streets are already ‘mapped’ through them, and they are no longer suburban residences, but ‘town-lots.'”

The Greatest Grid, a fine addition to our favorite books about maps, is a catalog of development and destruction, the end of nature and the beginning of urban living. When the grid eventually overtook the Brennan farmhouse, it too was destroyed. All was not lost for Poe, however. In the 1980s, the city council wanted to mark the writing place of the now famous author—they named the street after him.

Michelle Legro is an associate editor at Lapham’s Quarterly. You can find her on Twitter.