The 1890 police census was handwritten by officers in a total of 1,008 bound books, of which at least 894 books survived. After completing the initial enumeration of the 24 Assembly Districts that comprised New York City in 1890, city officials checked the census pages against the 1890 federal census. When it was apparent that many names in the Federal census were absent from the police census, cops returned to numerous addresses to supplement the original tally. The initial enumeration totaled 947 books, while the re-canvassing added 61 books covering Assembly Districts 19-24, about half of which are no longer extant.
The census books are not indexed. To find an individual, it is necessary to first have an address. To find an address, city directories are the most useful resource.
To pair an address with the census book in which the occupants are enumerated, and to match a census book with the relevant Assembly District and Election District (AD/ED), three options are available:
- Use the three-volume published guide Aid to Finding Addresses in the 1890 New York City Police Census: An Index of All Street Addresses / compiled by Howard M. Jensen. In these three volumes, book numbers are provided for Manhattan addresses, which are listed alphabetically. There is also a section of book numbers listed in sequence, with the corresponding AD and ED numbers. As noted in New York City Municipal Archives: An Authorized Guide for Family Historians, the 1890 police census is "virtually inaccessible" without the Jensen guide.
The website Steve Morse One-Step provides an AD/ED lookup for streets in Manhattan and the Bronx, but is not designed to search for an exact address; for example, selecting West 4th Street will show all the AD/ED common to West 4th Street.
- Descriptions of Assembly and Election Districts are sometimes found published newspapers in an election year, or when reapportionment takes place. New York State took a state census every tenth year on the fifth year between 1855 and 1925, the last year that the State Senate and Assembly used the New York State enumeration for apportionment, and initiated using the enumeration results of the federal census. There was no NY state census in 1885 and the subsequent state census took place in 1892. That year, New York State was highly divided along party lines about the accuracy of the 1890 federal census, which population numbers favored Republican representatives, and the accuracy of the 1890 New York City police census and 1892 New York State Census, which population numbers favored Democratic representatives.