For the study of the built environment, the fire insurance company atlases of the later 19th and early 20th centuries often provide the easiest access to the largest amount of information. Created to help insurance agents judge the risk involved in insuring properties of all kinds, they give a wealth of material about the location of buildings, their footprint, their materials and configuration. In the most detailed of these maps building materials are indicated by the use of various colors of water color applied to the building outlines and information about building heights, uses, fenestration, heating plants and other aspects of the building is indicated by labels and symbols. A key at the beginning of each volume explains the system used in that map. One thing to check carefully is the history of revisions. Although an atlas might bear the date 1899, the year it was first published, it is important to look to see if there were later revisions. Since the atlases were so labor intensive to make and so expensive, the companies often updated them rather than published entirely new atlases. To do this they sent agents to the cities to check on new developments. These were drawn on pieces of paper that were then pasted into the old books. The date of the last revision is effectively the date of the information in the album. Although there were many fire insurance atlas publishers in the United States in the late 19th century, by the early 20th century, the field was dominated by one company, the Sanborn company. The largest collection of fire insurance atlases is found at the Library of Congress, where copies of these atlases were deposited for copyright purposes. In recent years a large number of these maps has been reproduced by various companies. For Illinois the Chadwyck Healey Company has reproduced a great many Sanborn fire insurance atlases on microfilm. At UIC these sets can found on the third floor in the microforms area. Unfortunately, they are reproduced in black and white, but it is still usually possible to distinguish the various colors indicating building materials. The most important collection of original fire insurance atlases in the Chicago area can be found at the library of the Chicago Historical Society. The Ricker Library at the University of Illinois at Urbana al so has a very large collection.
The fire insurance maps reproduced here are found in the Rare Books Collection of the Special Collections Department of the University Library of the University of Illinois, Chicago. They are drawn from Elisha Robinson's Robinson's Atlas of the City of Chicago, published first in 1886, and then "annotated" and "corrected" over a period of years thereafter.