Exploring Sanborn Fire Insurance Maps

Sanborn fire insurance maps have been essential in understanding the history of urban areas in the United States for over a century. These maps offer a wealth of information about buildings’ ages, materials, and uses, as well as the layout of streets and alleys. In this article, we will explore the history and significance of Sanborn maps and their applications in historical research.

History of Sanborn Maps

Sanborn maps were first created by the Sanborn Map Company in 1866 to assist fire insurance companies in assessing fire risk. These maps were initially produced using black and white printing techniques and only featured basic information about the buildings they covered. However, over time, the maps became more detailed and included information such as the type of construction materials used in buildings, the number of stories a building had, and the presence of fire alarms or sprinklers.

The Sanborn Map Company continued to produce maps until the 1960s when technological advances in aerial photography and satellite imagery began to replace them. Today, Sanborn maps are primarily used by historians, urban planners, and architects to explore the history of urban areas and plan renovations or restorations.

How Sanborn Maps Were Created

Sanborn maps were created by surveyors who would walk the streets of a city, recording the dimensions and other details of each building. This information was then used to create a map, which would be printed on large sheets of paper. Each sheet covered a specific area of the city and was typically updated every few years to reflect changes in building construction or use.

Sanborn maps were typically printed using color-coded symbols to represent different types of buildings and hazards. For example, a red symbol might indicate a brick building, while a blue symbol could represent a wooden structure. Additionally, the maps would often include notes about specific buildings, such as the presence of fire escapes or the location of hazardous materials.

What Sanborn Maps Can Tell Us

Sanborn maps are an invaluable resource for historians looking to explore the history of a particular urban area. By examining the maps, researchers can learn about the development of different neighborhoods, the types of buildings that were constructed during specific time periods, and the ways in which cities grew and changed over time.

Sanborn maps can also provide insights into the social and economic conditions of a particular area. For example, maps from the early 20th century may reveal the presence of tenement housing, while more recent maps may show the expansion of commercial or industrial districts.

Using Sanborn Maps in Historical Research

Researchers can use Sanborn maps in a variety of ways to understand the history of urban areas. For example, maps can be used to investigate patterns of residential segregation or the growth of particular industries. Maps can also be used to explore the impact of natural disasters such as fires or floods on urban development.

Sanborn maps can also be used to create visualizations of urban areas at different points in time. By layering maps from different years, researchers can create animations or interactive maps that show how a neighborhood changed over time.

FAQ

What Cities Are Covered by Sanborn Maps?

Sanborn maps were produced for thousands of cities and towns across the United States. The maps are most commonly found for cities with populations over 10,000, but smaller towns and rural areas may also have Sanborn maps.

How Accurate Are Sanborn Maps?

Sanborn maps are generally very accurate, as they were created through careful surveying and precise measurements. However, the maps may not be completely up-to-date or reflect changes that occurred after the map’s publication date.

How Can I Access Sanborn Maps?

Sanborn maps are available in many libraries and archives across the United States. Many of these institutions have digitized versions of the maps that can be accessed online. There are also several commercial websites that offer access to Sanborn maps for a fee.

Can Sanborn Maps Be Used for Genealogy Research?

Sanborn maps can be a valuable tool for genealogy research, as they can provide information about the locations of ancestors’ homes or businesses. However, the maps may not be detailed enough to provide information about individual residents or employees.

What Are Some Challenges of Using Sanborn Maps?

One of the biggest challenges of using Sanborn maps is that they are often very detailed and complex, making them difficult to decipher. Additionally, the maps may be incomplete or outdated and may not provide a complete picture of the urban area being studied.

Sanborn maps are an invaluable tool for historians and researchers looking to explore the history of urban areas in the United States. By providing detailed information about buildings, materials, and hazards, these maps offer a wealth of information that can be used to understand the social, economic, and cultural conditions of different neighborhoods and towns. With their color-coded symbols and detailed notes, Sanborn maps continue to be an essential part of historical research today.