R&R uses Sanborn Insurance Maps to assist users in understanding the evolution of the structures they are viewing throughout the website. Although Sanborn Maps were constructed and updated in cities of any size, smaller communities and rural towns often were overlooked. Often they had so few structures that they were ignored, and no data exist for these communities.
Sanborn Maps were printed on large sheets depicting numerous city blocks. R&R has identified individual structures on these maps, corresponding to their 21st century address, to showcase the history of the home or commercial building. The images of the Sanborn Company were highly accurate and clearly represented a diagram of the structure on a specific location, time and place. However, the street numbers used to identify these locations have often been updated and don’t always correspond with the current street number or address. These images were not static diagrams, but rather a highly fluid look at changes in neighborhoods and specific structures. As the company updated their maps every few years, changes were recorded and reflected in the newer maps. For instance a house built in 1890 that was shown in yellow, a key color indicating of frame construction, could have been enlarged, destroyed by fire, moved or veneered during the interim period. Comparing Sanborn maps from successive decades of the same location often reveal major alterations that are of interest to the viewer.
R&R offers users a glimpse at one specific date when a structure was intact. Normally R&R’s Sanborn display is taken from early 20th century Sanborn maps, a time shortly after many houses were either first recorded or constructed. Subsequent maps might reveal significant changes to the structure, grounds, or neighborhood. For additional information on Sanborn Maps please see the attached links.
Informative links: http://www.loc.gov/rr/geogmap/sanborn/san4a1.html http://en.wikipedia.org/wiki/Sanborn_Maps