Editing Sanborn maps (section)

{{Short description|Detailed maps of cities and towns in the United States}}
{{Use American English|date = February 2020}}
{{Use mdy dates|date = February 2020}}
{{Infobox product
| title            = Sanborn maps
| image            = Sanborn Boston 1867 sheet 1a.gif
| image_size       = 
| caption          = Sanborn map of Boston from 1867
| type             = [[City map]]
| inventor         = [[Daniel Alfred Sanborn]]
| inception        = {{start date|1866}}
| manufacturer     = The Sanborn Map Company
| available        = Available
| current supplier = LightBox
| last production  = 
| models           = 
| website          = https://edrnet.com/prods/sanborn-maps/
| notes            = 
}}
'''Sanborn maps''' are detailed maps of U.S. cities and towns in the 19th and 20th centuries. Originally published by '''The Sanborn Map Company''' (Sanborn), the maps were created to allow [[fire insurance]] companies to assess their total liability in urbanized areas of the United States.  Since they contain detailed information about properties and individual buildings in approximately 12,000 U.S. cities and towns, Sanborn maps are valuable for documenting changes in the [[built environment]] of American cities over many decades.<ref name="keister1993">{{cite journal | last=Keister | first=Kim | title=Charts of Change | journal=Historic Preservation | volume=45  | issue=3 | pages=42–49 |date=May–June 1993 | quote=Stated simply, the Sanborn maps survive as a guide to American urbanization that is unrivaled by other cartography and, for that matter, by few documentary resources of any kind. }}</ref>

Sanborn held a monopoly over fire insurance maps for the majority of the 20th century, but the business declined as US insurance companies stopped using maps for underwriting in the 1960s. The last Sanborn fire maps were published on [[Microform|microfilm]] in 1977, but old Sanborn maps remain useful for historical research into urban geography.  The license for the maps was acquired by land data company Environmental Data Resources (EDR), and EDR was acquired in 2019 by real estate services company LightBox.<ref name=loc1>{{cite web|url=https://www.loc.gov/loc/lcib/9712/map.html |title=Library Announces Digital Map Project |website=Library of Congress|date=1997-12-01 |accessdate=2020-10-30}}</ref><ref name=real1>{{cite web|url=https://therealdeal.com/2019/05/13/silver-lake-backed-startup-lightbox-makes-even-more-re-tech-acquisition-noise/ |title=Silver Lake-backed startup Lightbox makes even more RE Tech acquisition noise |website=The Real Deal|date=2019-05-13 |accessdate=2020-10-30}}</ref>