Sanborn Map Company

The Sanborn Map Company was founded in 1867 with headquarters in New York City. Its purpose was to produce maps that would show "at a glance the character of the fire insurance risks of all buildings" in a give community. Since these maps had a very specialized use, "there were usually fewer than twenty orders for a single map sheet". Consequently, even though Sanborn maps are printed works, their rarity is similar to that of manuscript maps. The Sanborn Map Company ceased making its insurance risk maps in the 1950's, but paste-over correction sheets are still available for many urban areas.

From the description of Detroit insurance maps. (State Archive of Michigan). WorldCat record id: 40662011

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