Mapping Our Ancestors - Part II

Mapping Our Ancestors Part II   by Eliane Dotson

[This is the second article in a two-part series on using maps in genealogical research.  The first article focused on commercially-published maps, and can be found here: Mapping Our Ancestors Part I.]
Before I begin I must give a big thank you to Cassandra Farrell, Senior Map Archivist at the Library of Virginia, for her assistance researching and compiling the information for this article.
This article will review the types of government issued maps that can aid in genealogical research, including military maps, topographic maps, nautical charts, aeronautical charts, highway maps, and postal route maps.  Of course before you begin your journey into your ancestors' world, you must collect basic information first, such as the names, places and dates of your ancestors.  Get a sense for the towns, counties, and regions in which they lived.  Find out if they were in the military and whether they were involved in any battles or where they were stationed.  Once you have gathered this data, you will begin to see how maps can lead you to more information, and which types of maps may offer the most useful information.
Governments, whether at the country, state, or local level, have always been invested in generating and compiling maps.  Within the United States, there are a number of different agencies that have been involved in creating maps, including the United States Geological Survey, the General Land office, the Corps of Topographical Engineers, the Coast Survey, and the Army Map Service, among others.  Agencies sometimes shared information with one another, but alas, not always.  And as many of these agencies were focused on mapping different aspects of the world, their maps often show different features.
Military Maps

Military maps can be a great tool for genealogical researchers, although they are more limited in the regions they depict and in the time periods they represent.  However if your ancestors lived in the United States during the Revolutionary War or the Civil War, you may be able to find military maps with a lot of useful information.  As these maps were created to aid in planning military movements, they are some of the most detailed maps you can find, showing landowners, property boundaries, mills, plantations, farms, churches, roads, footpaths, railroads, bridges, ferries, streams creeks, and topography.  Many of these maps also show the planning of a battle and its aftermath, with fortifications, troop movements, and military sites.  Military maps can be helpful in locating an ancestor's property and its boundaries, the types of businesses and employment that was available in the area, and the roads and waterways that were used at the time.  They can also show the location of county courthouses to determine where records may be held.  Accurate and detailed maps were a necessity cartography, surveying, and mapping tools and techniques.
Desandroüins, Jean Nicolas, Plan du terrein à la rive gauche de la rivière de James vis-à-vis Jamestown en Virginie ou s'est livré le combat du 6 juillet 1781 entre l'armée américaine commandée par le Mis. de La Fayette el l'armée angloise aux ordres du Lord Cornwallis, 1781. Image courtesy of Library of Congress.

Military maps can be found in both manuscript form as well as engraved and printed form.  The Library of Congress Geography & Map Division ( holds a large repository of Civil War Maps, over 2,000 of which are digitized online, as well as a strong collection of American Revolution era maps, with over 800 digitized.  State libraries will also typically have a collection of military maps of their state and region, although their online resources are often limited.
Topographic Maps

Another type of government map that includes a wealth of information is the topographic map.  The United States Geological Survey was founded in 1879 and was charged with the "classification of the public lands, and examination of the geological structure, mineral resources, and products of the national domain."  While the first surveys focused on mining districts, they were extended at the end of the 19th century to include the study of the water supply, and then in the 20th century eventually to cover all other regions of the United States.  The topographic mapping of the entire US was finally completed in 1990.  The field maps were engraved on three separate copper plates, with each plate representing a different feature.  The first plate showed topography and was printed in brown; the second plate showed hydrography and was printed in blue; the third plate showed civil and public works and was printed in black.  The three plates were printed on the same sheet, resulting in a three-color lithographic printing process.
U.S. Geological Survey, Virginia - Maryland. Mt. Vernon Sheet, 1904. Image courtesy of Old World Auctions.

The features shown in black on these topographic maps are typically of most value to genealogical research.  They include public buildings, schools, churches, cemeteries, roads, trails, railroads, and bridges.  Also shown are fence lines, land grants, and boundary lines between counties, parishes, townships, and even individual properties.  Armed with a topographical map of your ancestor's town, you can identify where court records were kept, the boundary lines of their property, where their grave marker is located, and the overall cultural landscape in which they lived.
Topographic maps are identified by the quadrangle they represent.  Over time, many of these quadrangles were re-surveyed, with changes engraved on a fourth copper plate and printed in purple ink.  Comparing successive revisions of topographic maps of the same quadrangle will show the growth and evolution of the area over time.  Noting these revisions can give you a sense of how your ancestor's life would have changed during that time, such as regarding employment opportunities or land ownership.
The USGS ( has an extensive website, with their entire collection of historical topographical maps from 1884-2006 available digitized online through the USGS store ( and the National Map (
Coast Survey Charts

Established in 1807, the United States Survey of the Coast is one of the US government's oldest scientific organizations.  It was created to "provide for surveying the coasts of the United States" in order to address issues of national boundaries, defense, and commerce.  Of course coast surveys were intended to assist sailors in navigating the waters and are therefore limited in their depiction of land, showing between one half to three miles inland.  However, they do provide detailed information for areas along the coast of the US and along major lakes, bays, rivers, or tributaries within the US.  Onshore information includes topography, roads, settlements, farmsteads, and occasionally names of landowners.  The agency was renamed the U.S. Coast and Geodetic Survey in 1878, and became a part of the National Oceanic and Atmospheric Administration (NOAA) in 1970.  The Office of Coast Survey has digitized its collection of historical charts and offers them free to download through their site (
U.S. Coast Survey, City of San Francisco and Its Vicinity California…, 1853. Image courtesy of Old World Auctions.

Aeronautical Charts

In 1921, the United States Army Air Corps initiated an evaluation of aeronautical charts in an effort to develop a standardized map for visual aerial navigation.  Based upon this study, the Air Corps issued 63 air navigation maps covering most of the military routes in the United States.  Prior to 1926, these maps were jointly compiled by the Geological Survey and U. S. Army Engineer Reproduction Plant.  By 1926, the preparation of air maps shifted to the U.S. Coast and Geodetic Survey (under the Commerce Department) with the passage of the Air Commerce Act.  Maps from this point on were intended to merge the growing commercial airways system with the military network.  These aeronautical surveys were intended for pilots, air traffic controllers, and eventually the Federal Aviation Administration.  The charts show some unique information that is typically not found on other historical maps, including restricted or private use airports, abandoned airports, heliports, power plants, and open air theaters.  Although not central in a genealogists toolkit, aeronautical charts can offer helpful information, in particular regarding migration and travel patterns in the 21st century.  The Library of Congress ( has a comprehensive collection of aeronautical charts of the United States that were created in 1926.
United States Army Air Corps, Air Navigation Map No. 4 (Experimental) Washington. D.C. to Hampton, VA, 1929. Image courtesy of Old World Auctions.

State Highway Maps

Or course travel by car was much more common than air travel in the 21st century, with automobile road maps beginning to appear on the market around 1904 with Rand McNally's New Automobile Road Map of New York City & Vicinity.  Road navigation was difficult at the beginning of the century, as the road system was still under-developed with few paved roads and signage on roads was inconsistent or nonexistent.  Wisconsin was the first state to number its highways in the U.S., with signs erected in 1918.  Other states soon followed, however each state maintained its own set of numbered highways.  The US Numbered Highway System was finally created in the 1920s to create a uniform system of identifying major routes and interstate highways.  While commercial road maps were popular give-aways at filling stations from 1920-1970, state highway commissions also published official state road maps.

Department of Highways, Map of Accomack County Showing State and County Roads, 1932. Image courtesy of Library of Virginia Map Collection.

In addition to showing roads, these maps also identified the type and condition of the roads, mail routes, school bus routes, railroads, ferries, airports, schools, churches, and county court houses.  Color was often used to designate different types of roads on these state highway maps, making the legend an necessary tool in deciphering the map.  These maps can aid genealogists in finding old roads or towns that no longer exist, establishing how families moved across a state, and locating county boundaries and court records.  State and county highway maps can be found in local state libraries, as well as at the Library of Congress (
Postal Route Maps

US Postal route maps of counties, states, and regions were regularly published between 1830-1940.  These maps showed mail routes, post offices, distances between post offices, frequency of mail service, discontinued post offices, railroads, canals, towns and county boundaries.  The primary focus of these maps is post offices and railroad stations, so not all roads are shown, only those followed by a mail route.  Postal route maps of individual counties often show the exact location of houses.  Some postal route maps even give statistical information, such as population and population density, number of post offices, and miles of railroads and canals.  Genealogists use postal route maps to find old roads and railroads no longer in use, determine the approximate location of an ancestor's home, and identify travel and migration routes.  These maps can be found at the Library of Congress (, the National Archives' Cartographic and Architectural Section (, and at the National Archives in College Park, Maryland (

Post Office Department, Rural Delivery Routes Fairfax County, VA, 1912. Image courtesy of Library of Congress.

Putting It All Together

There are so many types of maps that can aid in genealogical research, it can be a bit overwhelming.  To simplify the process, follow these key steps:
  1. First gather basic information on your ancestors, including full names, dates of birth and death, and the known locations where they lived.
  2. Next figure out what information you are missing, or what additional questions you have about your ancestors.  Was your ancestor born in one city, but was laid to rest in another city, and you aren't sure what precipitated the move?  Are you missing birth, death or marriage certificates for an ancestor?  Do you want to understand what life was like for your ancestor?  Do you want to learn more about your ancestor's home town or neighborhood?  Did an ancestor's whereabouts suddenly become unclear, and you want to determine where to regain their trail?  Being specific about what information you need is critical in determining how maps can help you.
  3. Determine what type (or types) or maps have the information you need.  Many different types of historical maps, whether government issued or commercially produced, will offer similar information.  Sometimes several types of maps could suffice, so consider which type will have the most comprehensive or up-to-date information for the specific time period you seek, or which type might be the easiest to locate. 
  4. Locate the maps you need.  Throughout this two-part article I have listed resources for each type of map.  Ideally, first look at what sources are available online.  Online search functionality, whether on your favorite search engine or the search feature on a specific resource website, can often make it easy to find a specific map.  Also, digital images can be more useful than paper maps because you can zoom in and see great detail.  Once you have exhausted online sources, contact local libraries or public records offices to search for maps in their archives.
  5. Analyze the map for clues relating to your ancestors  Some of the key details to note are place names (including their exact spelling), transportation routes (both on land and water), economic development (such as local businesses, industries, or natural resources), decorative elements or images that provide more information about the time period, and textual elements (such as tables or notes on the map).  Ideally make a copy of the map to keep in your records, whether by downloading a digital image, taking a photo of a physical map, or making a photocopy of a map.  Make sure you also note where you found the map for future reference.
Using maps in genealogical research opens up a wealth of information that court records alone cannot provide.  Learning about who your ancestors were, where they lived, how they lived, and what their communities were like adds color and context to your family history.  Whether you've just begun to research your heritage, or you've already identified the last ten generations, don't forget to look to maps for a visual image of your ancestor's era. 
Guthorn, Peter J. United States Coastal Charts 1783-1861, Exton, PA, 1984.
Kashuba, Melinda, Walking with your Ancestors, Cincinnati, OH, 2005.