This land is your land
this land is my land
from California
to the New York Island...

Woody Guthrie, "This Land Is Your Land", 1940

We all know Manhattan as an island. But it wasn't always so! Manhattan used to be mostly a peninsula, because its northern bound was not in fact continuous water but a seasonal creek named the Spuyten Duyvil. Today, that creek survives in memory only in the name of the Spuyten Duyvil Bridge, a swing-open railroad bridge which connects Manhattan to the Bronx. It is currently used only by Amtrak traffic, but in its day it handled freight, passenger and all manner of trains into the island.

But we digress.

The notion of a ship canal across the northern end of Manhattan was attractive to both government and investors in the 19th century because New York City was both a very active port as well as the gateway to large amounts of ship traffic traversing up the Hudson. In order to reach berths in lower Manhattan, or to reach the Hudson River, ships approaching from the north were forced to detour all the way around Long Island, adding perhaps twenty-five miles to their journey. Although this wasn't much for transoceanic shipping to handle, the plethora of coaster traffic of the day was heavily affected. A light shipping run from Manhattan to, say, Bridgeport, CT or Boston would have a great deal of time, expressed as a percentage, added to its path - and be forced to leave the more sheltered waters of the rivers and Long Island Sound to venture out past Montauk into the wilder climes of the greater Atlantic.

If a path could be made between the wide, deep Hudson and Long Island Sound (via the Harlem River), not only could new routes be undertaken, but it would mean a whole new stretch of waterline on which piers and businesses could be built, a potentially lucrative real estate upgrade. In 1817, a narrow canal had been dug to permit small craft traffic to traverse south of Marble Hill in all seasons, dubbed the 'Dyckman Canal'. It allowed rowboats and small private sailing vessels to move across the upper part of Manhattan to the wider, western end of the Spuyten Duyvil creek, and thence to the Hudson. Steam vessels, however, were far too large to make the passage. A couple of corporations were formed in the first half of the 19th century to complete the canal, but both failed. In 1863, the Hudson And Harlem River Canal Company came into being with the goal of succeeding in joining the Hudson and Harlem rivers with a navigable canal. Actual construction began five years later.

The initial canal course was not the one we see today. The neighborhood of Marble Hill was first isolated by the small canal cut south of it, and the seasonal creekbed remained as its northern border. The new canal also had to contend with strategic priorities! At the very south tip of the Bronx, just where a straight-line canal would traverse from the northern tip of the navigable Harlem River to the Spuyten Duyvil bridge, lay the Johnson Ironworks. This foundry was a major supplier of guns and cast ammunition (shot and shells) to the U.S. military, and that path would require condemning the major portion of its works and isolating the southern part. Therefore, the initial canal (also known as the 'United States Ship Canal') looped south of the foundry.

The path of the canal contained a great deal of rocky terrain, and the dolomite sediment there required blasting. Steam drills were used extensively, and explosives detonated in their holes to break up the rock, which then needed to be cleared away to landfills in the area. The work was dangerous and labor-intensive. Nor'easters caused extensive damage to the project, including tearing away the dams erected at the east and west ends to permit the excavation as a dry task. A great deal of construction machinery was ruined by the flooding, and the canal was finished by dredging both the rock and the machinery away, while the drilling and blasting was done from that point on by divers.

The canal opened officially in 1895, and John Jacob Astor IV - a backer of the canal, and one of the world's richest men, who had speculated heavily on the real estate that the canal would improve into waterfront, was set on being the first man through it. To his dismay, however, three months prior to the opening ceremony a lowly steam tugboat - the Lillian M. Hardy - managed to traverse the entire route with its shallow draft, stealing his thunder. The official ceremony, months later, would be opened by the U.S.S. Cincinnati firing a broadside to signal the opening of the Spuyten Duvil bridge to ship traffic. A huge celebration took place, with hundreds of thousands showing up for the spectacle.

In 1916, part of the old creek was completely filled in, making the former island of Marble Hill contiguous with the Bronx. However, that neighborhood remains, to this day, administratively part of Manhattan. It votes for Manhattan representatives, it has a Manhattan ZIP Code, and if you are arrested in Marble Hill, you'll find yourself arraigned in a Manhattan court.

Eventually, in 1923, the ironworks were condemned anyway - and the path of the canal was modified. The southern part of the ironworks remained as a small island. If you look at the satellite images today, you can see a peninsula on the south bank, with baseball fields on it, where the island was joined to Manhattan once ships could pass to the north of it.