Sawkill

The Sawkill or Saw-kill (the Dutch place-name for Saw Mill Creek) was the largest hydrological network on Manhattan Island prior to the founding of the Dutch colony of New Netherland in 1624. This 13,710-metre long stream began "within four blocks of the Hudson River":

"A rill flowing east from the rocky ridge overlooking Bloomingdale Village, which rose near Ninth Avenue and 85th Street, flowed in a southerly direction through Manhattan Square, where it spread into a little pond, and then turned east, crossing Central Park to Fifth Avenue, receiving three tributaries within its limits, two from the north and one from the south. At 75th Street near Third Avenue it was joined by another stream. Near this junction the old Boston Post Road crossed it, and then from this point, the stream ran due east to its outlet near the foot of 75th Street"

emptying into the East River between two rocky points. Along its route the stream separated into two branches, with the name ‘Sawkill’ reserved for the southern arm of the creek. The name for the smaller, northern stream is undocumented, but is recorded by the Randel Map (1870) as entering the East River at 79th Street.

Undoubtedly, the stream received its name from the saw mill that existed for some time "in the bed of 74th Street, about 250 ft east of Avenue A.” The workers of the saw mill are thought to have been primarily the slaves of the Dutch West India Company, whose lodgings, stationed at the mouth of the Sawkill until at least 1639, were referenced as "the quarter of the blacks, the [The West India] company's slaves" in the first landmark map of Manhattan Island, the Manatus Map of 1639. It is thought that the slaves would use the stream to float the logs hewn by the mill to the East River, from which they would be transported to the newly established fort at New Amsterdam, at the southern tip of Manhattan Island, or thence to the Netherlands.

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Wikipedia