Every family historian eventually hits the same wall.
You know your great-grandfather owned land in Wayne County. You know roughly when. What you do not know is where that farm actually sat compared to the roads and towns that exist today.
A name in a census record and a county on a form only get you so far. At some point you want to see the actual ground. You want to stand, at least virtually, in the spot where your ancestors built a life.
Google Earth can get you there, and it is completely free. This guide walks through how to use it for genealogy, starting with the basics and building up to overlaying real historical maps onto the modern landscape.
What Google Earth Can Do That a Regular Map Cannot
A standard map app is built to get you from one place to another right now. Google Earth is built differently.
It renders the entire planet as a 3D globe using real satellite and aerial imagery, and it lets you layer other things on top of that imagery. That includes old maps, historical photos, custom pins, and travel routes.
The feature that matters most for family history is the ability to place an old map directly over a modern satellite view and adjust its transparency. You can look at an 1885 plat map and a 2026 satellite photo of the exact same coordinates at the same time, fading between them to see precisely where a homestead once stood relative to the roads and towns you would recognize today.
Getting Started With Google Earth Pro
Google has a few versions of Earth. There is a simplified browser version, a mobile app, and a full desktop application called Google Earth Pro.
For genealogy work, you want Google Earth Pro. It used to cost money, but Google made it free years ago, and it remains free today. You can download it directly from Google for Windows, Mac, or Linux.
Once installed, the interface centers on a search bar in the upper left, a Places panel below that for saving locations and overlays, and a toolbar across the top with tools for measuring distance, adding placemarks, and viewing historical imagery.
Google Earth Pro vs the Web and Mobile Versions
The browser and mobile versions of Google Earth are great for casually exploring the globe, but the tools that make it useful for genealogy live in the desktop Pro app.
The image overlay tool, which lets you import and align your own scanned map, is a desktop feature. So is the ability to bulk import a spreadsheet of addresses or coordinates and turn them into placemarks in one step.
If you are serious about mapping out family history, install the desktop version before you go any further.
Finding Historical Maps to Overlay
Before you can overlay anything, you need an old map worth overlaying. A few sources come up again and again in genealogy research, and each one is useful in a different way.
The David Rumsey Map Collection
The David Rumsey Map Collection is a free online archive built from one collector's personal library of more than 150,000 historical maps, ranging from the 1500s through the early 1900s.
A large portion of these maps have already been georeferenced, meaning someone has done the technical work of matching points on the old map to their real modern coordinates. You can download a KML or KMZ file directly from the collection's website, and it will open in Google Earth already aligned to the correct spot on the globe.
This is the easiest way to start, since there is no manual alignment work required on your part.
USGS Historical Topographic Maps
The United States Geological Survey has scanned and published its entire historical collection of topographic maps, covering printed maps from 1884 through 2006, through a free tool called topoView.
These maps show far more local detail than a national atlas, including elevation contours, small waterways, rural roads, and the names of towns and features that may no longer appear on a current map. TopoView lets you search by location and download the map for that area as a KMZ file, ready to open in Google Earth.
For anyone tracing a rural ancestor, this is one of the most useful free resources available.
County Atlases and Plat Maps
If you want to see your actual family name printed on a parcel of land, county atlases are usually where you will find it.
Starting in the 1870s, publishers went county by county across much of the United States producing detailed atlases that showed individual property lines with the landowner's name written directly on their parcel. These are sometimes called plat maps, and they are genealogical gold when you can find one that covers your ancestor's township.
You can often find these atlases through a state archive, a county historical society, or a university library's digital map collection. Search for the county name along with terms like "1880 atlas" or "plat map" to see what has been digitized.
Unlike the Rumsey and USGS collections, these atlases usually come as a plain scanned image rather than a ready made overlay file. That means you will need to align it yourself, which is the next step.
How to Manually Overlay an Old Map Onto Modern Google Earth
Once you have a scanned map saved as an image file on your computer, aligning it in Google Earth Pro is a fairly straightforward process.
In the Add menu, choose Image Overlay. A dialog box will appear asking you to browse for your image file and give the overlay a name, such as "Wayne County 1885 Atlas."
Once your image loads, it appears as a rectangle on the globe with green handles at the corners and edges. Drag those handles to stretch, rotate, and skew the old map until its features line up with the modern satellite view underneath it.
Use the transparency slider in the same dialog box to fade the old map in and out while you work, so you can see the modern imagery through it and check your alignment as you go.
The trick to a good alignment is picking landmarks that have not moved. Rivers, the bend of a creek, a rail line, or the center of a town square tend to stay put even as roads get rebuilt and fields get subdivided. Line up two or three of those fixed points first, then adjust the rest of the map around them.
Once everything lines up, click OK to save the overlay to your Places panel. From there, you can right click it and choose Save Place As to export it as a KML or KMZ file, which preserves your work so you can reopen it later or send it to a family member.
Using the Historical Imagery Time Slider
Old maps are not the only way to look backward in Google Earth. The app also stores years of actual satellite and aerial photography for most of the planet.
Click the clock icon in the toolbar, or select Historical Imagery from the View menu, and a time slider will appear showing every date for which imagery is available at your current location. Drag the slider and watch the same patch of ground change year by year.
Coverage varies by location, but many areas in the United States go back to the 1980s or earlier, and some rural regions have imagery dating to the 1930s. This is especially useful for more recent ancestors, since you can sometimes watch an actual farmhouse still standing in an early photo before it disappears in a later one, or see a rural crossroads slowly turn into a suburb over a few decades.
Placing Your Ancestors on the Map
Once you have historical context loaded in, the next step is marking the specific places that matter to your family's story.
Use the placemark tool to drop a pin on a homestead, a church, a cemetery, or the port where an ancestor first arrived. Give each placemark a name and a short description with whatever details you know, such as a date range or a source citation.
If you have a longer list of addresses, Google Earth Pro can import them in bulk from a spreadsheet through File and then Import, matching each address or set of coordinates to a new placemark automatically.
For a family that moved several times, connect the placemarks with the path tool to draw a line showing the full route, whether that is a single move from one town to the next or a journey across an ocean and then across a continent. Seeing a migration drawn out as an actual line on a map tends to make it click in a way that a list of dates never quite does.
Saving and Sharing What You Find
Everything you build in Google Earth, from map overlays to placemarks to migration paths, lives in your Places panel until you save it somewhere permanent.
Right click any item and choose Save Place As to export it as a KML or KMZ file. These files are small, easy to email, and open automatically in Google Earth on anyone else's computer, which makes them a simple way to hand your research off to a sibling or cousin working on the same family line.
You can also use File and then Save Image to export a high resolution picture of what is currently on screen, which is handy if you want to drop a screenshot of the old homestead location into a written family history or a printed keepsake.
A Few Things to Keep in Mind Before You Trust Old Maps
Old maps are a wonderful research tool, but they were made by people working with the surveying technology of their time, and that technology was not always precise.
Early maps, especially anything before the 1900s, can be off by a noticeable distance once you compare them to modern satellite imagery. County boundaries shifted over the decades in many parts of the country, and place names changed too, so a town or township that no longer exists under that name might still show up on an old map exactly where you need it.
Treat a map overlay as a strong visual clue rather than a legal survey. If you need to confirm an exact property boundary for something like a deed or a land dispute, cross reference the map against actual land records at the county courthouse or a state archive.
For the purpose of understanding your family's story, though, an approximate location is often more than enough. Knowing your ancestors farmed the land near a particular bend in a river, or lived a short walk from a church that still stands today, adds a kind of grounding that a birth certificate alone cannot give you.
Why This Kind of Research Matters
There is something different about seeing an actual place instead of just reading a name on a document.
A county name in a census record stays abstract. A satellite photo of the exact patch of ground where your great-grandfather planted crops, with an old plat map faded over the top showing his name on that parcel, turns into something you can actually picture. It becomes a place instead of a fact.
That kind of detail is exactly what tends to get lost between generations. Someone in your family may still remember which hill the old farmhouse sat on, or which road led to the church where three generations were baptized. Once that person is gone, the map is often the only thing left that can point you back to the spot.
If a project like this turns up a place, a name, or a story worth holding onto, it is worth writing down somewhere it will actually last. Memoracy gives you a simple daily prompt to record the stories and places that matter to your own life, so the next generation in your family has more to go on than a name on an old map.
Sign up and start your first story on Memoracy today.
