The author was inspired by this detail of Manhattan from a British Headquarters Map drawn during the American Revolution, c. 1780. It provided a clear view of the natural landscape of the island before the shores were expanded, hills were levelled and streams and wetlands were buried under.
The author and illustrator laid a modern road grid of the city over the British Headquarters Map. Note that many of the old roads line up with the modern ones. Also of interest is the expansion of the shoreline.
On another map, the author and illustrator added the city's modern building footprint to 18th-century British map.
Another view of Manhattan then and how. In 1609, between 300 and 1,200 people lived on the island. Today it is home to millions.
The West Side then (hills and marshes) and now (Battery Park City and the West Side Highway).
Beavers were once abundant along the shores of Manhattan and are still found on seal of New York City.
Northern Mannahatta/Manhattan, where some of the original forest is still intact.
Lower Manhattan: The Collect Pond seen on the "before" picture on the left was the most important natural feature of the area. Its remnants now lie under Canal Street, which itself lies on top of the canal built to drain the pond.
The east side of Mannahatta/Manhattan
The Upper East Side and Harlem: In the picture on the left, the native people of Mannahatta, the Lenape tribe, burn a swath of land to prepare it for farming and hunting.