In my preliminary research into African-American(A/A) records I have discovered that an A/A showed on records without a surname prior to the 1870 census. When they did show it was usually and most often as the property to some white settler and they were identified by first name(maybe) gender and age only.
But I do not know if in New York they were kept as slaves in the 1700/1800's or as freemen/employees.
In my research I have an interest in the "Shuler Family" who, through the marriage of Lawrence Shuler to the widow Dubois, took over a section of the Harrison Patent circa 1770. The estate holdings were in New York: Montgomery/ Florida County, but it turns out that in the 1830's they did not have slaves.
The source of this information is from this site: http://darcisplace.com/darci/shuler.htm.
This is where an anomaly appears because in the 1840's a John Shuler, "Negro from New York," appears in the records of TuscaroraTownship, Brant County, Ontario which is part of the Six Nations Indian Reserve. He married a negro named Sarah (born Sally who was the adopted negro child in the story, "The Abduction of White Peter" of the early 1800's), raised a family and died by the 1900's.
How could he have a surname in the 1840's if it was not allowed unless he came from the estates of the previously mentioned Shulers and adopted the surname on his arrival?
As to the age of John Shuler, "Negro," as a means to identify him on any estate census I can only estimate that he was born 1800-1810 in New York. All Ontario census records of him show an inconsistency with his age: in 1861 he is 60 years but in 1871 he is 50 and in 1881/91 is 69 and 79 years respectively.
John Shuler, "Negro from New York," was my great-great-grandfather and his daughter Mary, my great-grandmother, married George Edwards who was supposidly of French origins. He may have been native but we have never been able to find records on him and he and Mary just disappeared by the 1881 Canadian census leaving their two sons, Fred and George, with the grandparents on the reserve.
Most of the other Shuler children also disappeared and may have returned to the U.S. after the 1870's.