100+
Years of Records
1736 - 1840
These 275 records represent named individuals -- each a person with a name, a family, a life -- whose existence is documented only through the legal and administrative records of those who enslaved them. A further 134 unnamed individuals are referenced in the same records, listed as "a black man," "four children," or simply tallied as a number in a census column.
Individuals by Decade
Birth Records (child role)
Family / Kin (parent role)
All 275 individuals carry datable events; peak documentation falls in the 1800s-1810s, reflecting the abolition-era record-keeping that followed New York's Gradual Emancipation Act of 1799 and New Jersey's Act of 1804. The shift from Legal/Estate (orange) in the 1700s to Birth Records (blue) in the 1800s and Freedom Documents (green) in the 1810s-1820s shows how abolition-era statutes reshaped the documentary record.
How We Know These People
Type of historical record documenting each individual (275 records across 275 individuals)
Sex, As Recorded
273 of 275 individuals have sex recorded in source documents; 2 records silent
Ages at Time of Record
Age category established for 261 of 275 individuals; 14 records silent on age
Where the source was genuinely silent — often in legal proceedings — we record “Source silent” rather than leave the field blank.
Largest Enslavers and the People They Enslaved
Records attributed to specific identified enslavers (the project has documented 72 enslavers with primary-source documentary evidence across the Van Kouwenhoven-Conover family (unproven and non-family figures excluded)).
Geographic Reach
Enslaved people documented across 7 counties in New York and New Jersey
74
New York / 2 counties
Kings (Brooklyn / New Utrecht / Flatlands) / New York (Manhattan)
198
New Jersey / 5 counties
Monmouth (Freehold / Middletown / Manalapan) / Middlesex (South Brunswick / South Amboy / West Windsor) / Somerset (Franklin / Montgomery) / Bergen / Hunterdon
Resistance & Flight
9 individuals documented as having run away or been pursued
Abolition Context
1780 -- Pennsylvania passes first Gradual Abolition law
1785 -- New York Manumission Society founded
1799 -- New York Gradual Emancipation Act
1804 -- New Jersey Act for Gradual Abolition
1817 -- New York legislates end to slavery in 1827
1827 -- Full abolition in New York on July 4th
1850 -- Passage of the Fugitive Slave Act
1865 -- 13th Amendment ends slavery in New Jersey
Lives Documented Across Multiple Records
20 individuals appear in two or more documentary events, allowing a partial life-trajectory to surface -- a child's birth registered alongside her later manumission, an enslaved man inventoried at probate then freed nine years later, or a mother whose successive births were each separately recorded under New Jersey's 1804 gradual-abolition statute.
Dated Life Trajectories
10 individuals documented through more than one kind of record
Mothers with Multiple Children
10 mothers had multiple children registered under abolition-era statutes
Number of recorded children per mother. Each child's birth had to be registered under New York's 1799 or New Jersey's 1804 gradual-abolition statute.
In a single moment in 1790 -- at the first U.S. Federal Census -- Cowenhoven family heads enslaved 60 people in Kings County, New York alone, distributed across 9 households in New Utrecht, Brooklyn, and Flatlands. Most of these 60 are not among the 275 named individuals on this page; the census schedule lists them only by tally under each enslaver's name. The 275 documented above are individuals whose names survive in other records -- wills, manumissions, birth registrations, court files. The 60 of 1790 are a reminder that for every named person, many more were often held in the same households whose names history has not preserved.
Census Snapshot — 1790 U.S. Federal Census, Kings County, New York
Primary Source Types
These individuals are documented through a range of official records -- each record a fragment of a life otherwise lost to history. For links to all archives and an extensive bibliography, see the
Sources page.
Monmouth County Birth Records
Town of Brooklyn Manumission Records
Town of New Utrecht Manumission Records
NY Court of General Sessions Files (1704-1844)
NJ Supreme Court Case Files (1704-1844)
Probate Records & Wills
1790 US Federal Census, Kings County NY
NJ Slavery Records Database
NY Family Papers (CBH, NYHS, NYPL, NYSA, NYCMA)
NJ Family Papers (MCHA, NJSA, RUSC)
Middlesex County Birth Records
Somerset County Manumission Records
Monmouth County Manumission Records
Dutch Reformed Church Records
Newspaper Notices