I recently have read a few articles about New York City's Potter's field on Hart Island.
According to Wikpedia's article Hart Island (New York) and a New York City Corrections Department history page an estimated 750,000 to 1,000,000+ people have been buried in mass graves from 1868 to Present and burials continue at a rate of about 2000-3000 burials per year currently.
Per the articles:
The records of the coffin row-and-column placement are kept between five and 10 years.....those plot burial records are turned over to the Municipal Archives.
And some of these records post 9/1/1977 -> approximately 2007 have been made available.
In 2009 the digital mapping of grave trenches using the Global Positioning System was started. In 2013 the New York City Department of Correction created a searchable database on its website of the people buried on the island starting in 1977 and it contains 66,000 entries.4
The Hart Project website allows you to search 1980 to 2008 and Find-A-Grave has some sort of search but doesn't match the Hart Project, FamilySearch's New York Death Records do not seem to completely cover the period from what I can tell, and the NYC Department of Corrections' Hart Island Lookup Service has more recent records.
From these searches I was able to locate a few possible names of interest.
I reviewed similar NYC questions here. The New York City Department of Records' website has a genealogy section, but it is for vital records searches; there is no cemetery search in their List of Holdings. The Vital Records search requires specific searches and there does not seem to be a way to search for all Hart Island Burials.
Are earlier Hart Island specific records or indexes available elsewhere online from the 1868 to 1980?