Sanborn Maps



Portion of map of State Street and S. Center Street.
Image from 1914 Sanborn Map, updated through 1929.

Fire insurance maps were originally created as a means for insurance companies to underwrite policies for buildings that could not be inspected first-hand. Such maps are often referred to as "Sanborn maps" in reference to the Sanborn Company, based in New York City, that was responsible for producing the majority of fire insurance maps. Today, these maps are a useful resource for researching history, genealogy, preservation, urban geography and planning, and sociology.

Sanborn maps are bound in large volumes of numbered sheets. Each begins an index of streets and addresses, an additional index that includes the names of churches, businesses, and schools, and a map of the overall metropolitan area that indicates on which sheet to find certain blocks or areas. Each map sheet includes outlines of each building and outbuilding, the location of windows and doors, street names, street and sidewalk widths, property boundaries, building use, and house and block number. The maps also indicate information about each structure's building materials including framing and roofing, as well as locations of fire hydrants, water mains, gas mains, and often names of public buildings, businesses, and churches.

Portion of skeleton map showing lots
and buildings on Liberty Street
between Seward and Nott Terrace.
From 1914 Sanborn map.

To maintain accuracy and reduce production costs, updated drawings of new or altered buildings or lots were pasted on top of the old maps until a new volume was published. Occasionally, maps of some blocks include a base "skeleton" map outlining lots and properties.

Editions of Sanborn Maps in our library: City of Schenectady – 1884, 1889, 1892, 1894, 1900 (updated to 1912), 1914 (updated to 1924 and 1929), 1930 (updated to 1949/1961). Rotterdam Junction – 1913. To assist researchers in fully utilizing these maps, we also have information located nearby that explains abbreviations and notations used on the maps and offers suggested uses for Sanborn maps by genealogical researchers.