New York City Property Map Collections at NYPL: About

A cadastral is a map that documents the boundaries of land ownership; this style of map is often simply referred to as a "property map," and was originally used to ensure reliable facts for land valuation and taxation. The examples included at right [A1-A3] are typical of this map type in that they show the boundary of the property line and include the names of the landowners. Tax lots may include complete names, first initial with last name, surnames only, the estate name, or combinations of all of the above. In a few instances, like the example map of Flushing [A3], dimensions of the lot are also included.

Fire insurance maps, more commonly known as “Sanborn maps” or simply “Sanborns,” are sheet or atlas maps that were designed to describe the built environment of a city and were created to allow insurance companies to assess their total liability in urbanized areas. The images at right [B1-B4] are scans from a 1910 Manhattan Sanborn atlas found in the Digital Collections and include title page [B1] , location map index with key [B2]. street index [B3], and map plate [B4]. The title page includes the name of the borough(s) depicted as well as the year the atlas was published which may also indicate the approximate year the survey was conducted. (However, be sure to look for correction dates!) The location map index includes streets and physical landmarks that allow users to locate the specific plate the property is illustrated on.  The key below the location map describes the meaning of the various symbols, numbers, abbreviations, color tinting, etc. used by the map makers to describe the specific features of the buildings and real property shown on the map. The street index enables users to locate the map plate by address and in more recent atlases via block & lot number. The final example shows a typical map plate where we can see a depiction of the Library, Bryant Park, the old 6th Ave. elevated train station at 42nd St., and an adjacent block.         

A topographical land survey shows the height, depth, size, and location of any man made or natural features on a given parcel of land, as well as the changes or contours in elevation throughout the parcel. The facsimile of the British head quarters map [C1] and Egbert Viele's survey of Manhattan [C2] shown at right are both examples of early topo maps that depict the geography and relief of the island in an artistic manner using hachures and shading. The cross-hatching shows orientation of slope, and through their density, the map maker expresses overall steepness.  Whereas the maps of the Bronx [C3] and Staten Island [C4] are examples of contemporary surveys that were the results of a much more scientifically rigorous process that expresses changes in elevation with contour lines and spot height calculations. This map type rarely includes the names of landowners, however they often provide clues as to the ways in which the land was parceled off or subdivided as well as indications of land use at the time of survey.  Quite often land surveys created at smaller scales will include greater detail and may also include building footprints, depictions of vegetation, and landscaping.    

Real property auction maps, sometimes referred to as "farm maps," are sheets or pamphlets created by auctioneers containing maps, birds-eye views, and or descriptions of land for sale.  Most often they will show large parcels of farmland or private estates divided into smaller plots of land intended to be improved with the addition of new residential subdivisions and or commercial districts. 

Figures D1 and D2 at right are examples of typical single sheet auction maps which usually include three features: a title, a drawing of the land, and descriptive text.  The title most often includes a brief description of the land for sale and the name of the deceased or their estate. The illustration shows adjoining streets, the boundaries of the existing or newly created lots, buildings, and sometimes the names of surrounding property owners. There may also be additional text that describes the parcel of land in greater detail and may include the name of the auctioneer as well as the date, time, and location of the public auction.       

Figures D3-D6 are scans from a multi page brochure announcing the sale of a large plot of land in the Bronx. Like single sheet auction maps, brochures will include titles, maps, and descriptive text, but may also include bird's-eye views of the property and surrounding area [D3]; location maps showing connections to mass transit, parks, etc. [D4] ; detailed tax lot illustrations [D5]; and a paragraph written in the form of advertisement describing all of the supposed benefits of owning a home at the location [D6].   

To request material and reserve a seat in the Map Division reading use your NYPL library card to book a seat online.  If you have any questions about our collection or inquiries related to your research email us at maps@nypl.org or you can request a virtual consultation with a reference librarian.