Frequently Asked Questions

Here are some answers to your questions...

What is Genealogy4D?

We provide collections of map markers of genealogical events and places. Our goal is to establish that a person was in a specific location on a certain date in history. shows your ancestors in context of their neighbors and historical timeline of the area in which they lived.

How do I use Genealogy4D

You can browse the map or "fly to" any location by State/County. You can also search markers in each county to locate your ancestors or their neighbors. Use the filter function to help narrow down searches.

If you have census records for this ancestor it can help. These maps are the modern subdivisions (a.k.a. townships). But, many times you can find the same township names that were listed in the older census records.

How do you decide where to add markers?

We try to focus on areas where we can generate the most markers that have the most genealogical value and interst.

You can also post the place you want on our Facebook page or tweet it to us @genealogy4d.

We prefer places we can find the most markers in the shortest amount of time. We also prefer places that have the most interest to the most people. Most of all, we prefer places our customers want.

We are adding new markers constantly. Currently the markers are more heavily populated in the rural areas and in the Midwest. As we grow we will add more urban areas and reach all of the U.SA. Later we hope to expand to other countries as well. Regarding dated markers, our initial focus will be the 19th century because 1800-1900 will be the best range for genealogical research using these types of maps. However, as we add more markers we will expand into the 1600's, 1700s, and 1900's. In the future we are planning to add a premium feature to allow you to get customized research.

How do you decide which states to include?

We give priority to states where markers are easier to collect and where more people have common genealogical interest. Eventually we want to have markers from every state in the United States and international as well. Generally we will follow the National Road from Ohio to Missouri, then fill in surrounding states as we can. Our goal is to cover any genealogical event or structure we can put on a map.

Where do you get the information for the markers?

Some of our sources come from publicly available databases such as United States Geological Survey (USGS) or BLM (Bureau of Land Management). We also are in process of gathering markers from all kinds of sources such as land records, census records, directories, probate records, vital records, military records, etc.

How accurate is the information?

Our goal is to be accurate up to approximately 1/4 of 1 mile in rural areas and within 1 city block in urban areas. Old plat maps were hand-drawn and not always intended to be precisely measured, so many markers could be up to 600 to 700 feet from the actual location. We do not draw boundaries around land plats. Our maps are not intended to show precise property boundaries. Our goal is to indicate that a person or group was in this location at a specific time. Some special markers are shown as proximity markers. These markers are generated from algorithms that are designed to make "educated guesses" about the location of the marker. Each marker has a detailed explanation of why the marker was located there. In some cases these markers can be many miles away from the actual location of the event. Please examine each marker's description and make your own decision about its accuracy based on the information in the data and your own research.

Why are there duplicate markers for the same feature?

We put a marker down every time we find a new source that shows a place or indicates an event. By marking a time range for each source we can show that a person or place was there over a period of time.

What do the colors of the markers mean?

Marker Colors:

  • Blue: Water Feature
  • Brown: Property, Land, Address
  • Copper: Historical Event
  • Gold: Place
  • Green: Natural Features
  • Orange: Civil and Surveys
  • Purple: Social Features
  • Yellow: Census

Markers List:

  • Airport
  • Arch
  • Area
  • Arroyo
  • Bar
  • Basin
  • Bay
  • Beach
  • Bench
  • Bend
  • Bridge
  • Building
  • Canal
  • Cape
  • Cemetery
  • Census
  • Channel
  • Church
  • Civil
  • Cliff
  • Crater
  • Crossing
  • Dam
  • Events
  • Falls
  • Flat
  • Forest
  • Gap
  • Glacier
  • Gut
  • Harbor
  • Hospital
  • Island
  • Isthmus
  • Lake
  • Lava
  • Levee
  • Locale
  • Land Record
  • Military
  • Mine
  • Miscellaneous
  • Natural
  • Oilfield
  • Occupation/Business
  • Patent
  • Park
  • Pillar
  • Place
  • Plain
  • Populated Place
  • Property
  • Post Office
  • Private
  • Range
  • Rapids
  • Reserve
  • Reservoir
  • Religious
  • Railroad
  • Residence
  • Ridge
  • School
  • Sea
  • Slope
  • Spring
  • Structure
  • Summit
  • Survey
  • Swamp
  • Tower
  • Trail
  • Tunnel
  • Unknown
  • Valley
  • Well
  • Woods


Markers are gathered from various sources. Some are in the public domain and can be downloaded from source sites in other formats. Some of the markers are derived from privates sources and are used here by permission.

All other markers are geolocated using Genealogy4D software or members. ©2014 - 2017 Genealogy4D. All rights reserved.

Accuracy. The accuracy of the location of each marker varies depending on source. Some markers are taken from maps which were drawn by hand. In these cases, markers may be up to 1/8 to 1/4 mile away from the actual position.

Sometimes markers which have been imported from later sources are more accurate because they have been carefully surveyed and entered into a database. In other cases markers which have earlier sources may be more accurate because precise locations are lost for historical locations over time. Earlier maps may actually be more accurate.

If you want to determine the accuracy of the location of a marker please compare it with the original source information mentioned in the citation. We welcome feedback and corrections.

Duplicate Markers. In order to account for changes to a marker over time, the markers are repeated each time they are mentioned by a source. By using the folders and the timeline you can filter out some of the duplicates. If the position changes from source to source, it does not necessarily mean that the location is changing. It may mean that the source information is inaccurate or not precise in the location. However, in rare occasions it may also indicate that the position of the location has changed over time.

How does the time feature work?

Marker Time. Some markers are assigned to a specific time range depending on type of marker and the source from which it originated. The intent is to loosely approximate the time this marker may be accurate during a time period in history.

Land records generally become visible during the year they were dated. They will be visible for a number of years from that date until it may be reasonably assumed that the ownership might have been sold to another person. As more land records become available on genealogy4d, these time ranges will be improved to increase the accuracy. Markers taken from plat maps, directories, censuses, are generally timed for a range before and after the source was published. The goal is to show that this marker was effective at some time in this time range. Markers may or may not be effective during this time range. Markers taken from USGS sources and other sources without specific dates are generally considered to not have a specific time assigned. They should be visible during all time periods even if they point to a modern location.