Fire Insurance Atlases

The Southeastern Architectural Archive houses a rich collection of fire insurance atlases, the output of civil engineers, surveyors and insurance adjusters. Although the SEAA retains fire insurance atlases for many municipalities in Louisiana and Mississippi, its strongest holdings document the New Orleans metropolitan area, with coverage dating from the 1860s to 1978.

For the study of the built environment, municipal fire insurance atlases are an excellent resource. Created to help insurance agents judge the risk involved in insuring properties of all kinds, they convey a considerable amount of information:  lot location, external dimensions, building footprint, disposition and context. The most detailed of these maps identify water resources, including pipes, sprinklers, drainage canals and cisterns.  Frequently, construction materials, heat sources, fire hazards, fenestration, and functions are denoted by either symbolic or color-coded designations. Some atlases list property owner and assessed value, policy duration and insurance costs.  At the beginning of most atlases, an index map outlines the boundaries of the municipal district and its plats.

Sanborn Fire Insurance Index Map for Plaquemine, LA. 1900.
 

The most comprehensive fire insurance atlases are those that were made by the Sanborn Map & Publishing Company, Limited. Founded by surveyor Daniel Alfred Sanborn on 3 Feburary 1876, the company rapidly became the largest producer of maps in the United States.  These maps were printed with the lithographic process and bound into enormous volumes.  Aside from the index maps, Sanborn maintained a consistent scale of fifty feet to one inch (1:600), cross-sectioned in squares. Updates were lithographically printed onto individual sheets called "slips" and then cut and pasted into the album books.  A given volume may contain many layers of these so-called "pasters," which represent land use changes, redevelopment, renovation and infill.

Comparing fire insurance atlases for successive years may chart significant changes to individual structures as well as to the urban fabric.  Viewed interpretatively, these maps may represent regional building typologies and document socio-historical precepts associated with the built environment or reveal the ways in which urbanscape is constructed and constricts, and the historical dimensions of risk assessment.

For a listing of Sanborn Atlases retained by the Southeastern Architectural Archive, consult:

Inventory of Sanborn Fire Insurance Atlases in the Southeastern Architectural Archive