More on the "swamp"

In 1734, this tract was sold for 200 pounds to Jacobus Roosevelt who
divided it into 50 lots and established on them several tanneries
(large leather center into at least the end of the nineteenth century)
More immense fortunes have been made about that region than any other
of the city. The swamp had been leased to Rip Van Dam for 21 years and
20 shillings a year" from Gerardius Beekman (Stone 1872:91)


Stone, William Leete
1872 History of New York City, New York

I think this was one of the rare old business books in the Huntington
Free Library in Westchester Square, Bronx, NY formerly housed an
ethnography collection of the Heye Foundation the collection was moved
as part of the Smithsonian Museum of the American Indian but the
library remains.

Later "Old Man's Swamp" was known as:

Beekmans Swamp, became a leather goods center (Moscow 1978:27)

Moscow, Henry
1978 The Street Book: An Encyclopedia of Manhattan's Street Names and
Their Origins, Hagstrom Co., NY Reprinted in 1979.