OpenHistoricalMap/Contributing
Welcome to OpenHistoricalMap! This page is here to help you get oriented. If you're coming here from OpenStreetMap, you will feel right at home. Otherwise, we hope you will find wiki-style mapping as exciting and fun as we do!
This is a rudimentary guide to editing OpenHistoricalMap. For more detail, consult a guide to editing OpenStreetMap, such as Beginners Guide 1.3. There are also good tutorials on LearnOSM and on TeachOSM.
Basic use
Visit www
If you zoom in far enough, the 
Query features button on the right side of the map lets you click on anything you see on the map to reveal more details about it in the sidebar. These details include tags as well as a brief summary from Wikipedia, if available.
Create an account
Before you can contribute to OpenHistoricalMap, you need to create a free login account on openhistoricalmap.org. If you already have an account at openstreetmap.org or this wiki, you won't be able to use it directly on OHM, but you'll likely be able to choose the same user name to avoid confusion.
Projects
When considering starting out in OpenHistoricalMap, it can be really helpful to think about specific projects. If you decide on a project, it's a good idea to create a page for it under OpenHistoricalMap/Projects. In fact, you should probably visit that page and see some of the things people have chosen to do. Some projects are really large. For example, the OpenHistoricalMap/Projects/American Civil War project is huge. As of this writing the folks working on it have chosen to focus on smaller sub projects.
It is recommended that individuals starting projects add some form of contact information, perhaps a link to their personal wiki talk page, to the project page. This facilitates coordination if others wish to get involved in these projects.
Editors
OpenHistoricalMap works with the same editors as OSM.
iD
The more basic method of contributing to OpenHistoricalMap uses a Web-based editor called iD. To access iD, visit OpenHistoricalMap's homepage, zoom in, and click the Edit button.
The first time you open iD, it gives you an opportunity to complete an interactive walkthrough tutorial. We highly recommend that you spend a few minutes completing this tutorial to familiarize yourself with the mechanics of editing the map. If you skip the tutorial, you can return to it at any time via the Help button on the right side of the map.
Rapid
Rapid is a fork of iD that excels at editing dense map data. An experimental instance of Rapid is available at https://rapid.openhistoricalmap.org/. This instance connects to the OpenHistoricalMap database but otherwise has yet to be customized for OpenHistoricalMap. This GitHub issue tracks the work to make Rapid more suitable for OHM editing.
JOSM
- Main article: OpenHistoricalMap/JOSM
JOSM is a more advanced alternative to iD, especially useful for large-scale tasks like imports and mapping international boundaries. We use the same official distribution of JOSM that OSM contributors use, but configure it to connect to the OHM server instead:
- OSM Server URL:
https://www.openhistoricalmap.org/api - Overpass server:
https://overpass-api.openhistoricalmap.org/api/
Go Map!!
Go Map!! is a full-fledged editor for iOS, iPadOS, and macOS devices. To edit OpenHistoricalMap, change your server settings:
- Tap the
button in the lower-left corner, then go to Advanced Options. - Tap “▼” which will then list available OSM servers. Select “OpenHistoricalMap”.
The start_date=* and source=* tags are always located at the bottom of the “Common Tags” page. Tap the “Customize Presets” button to add the end_date=* field to “Common Tags”.
ohm-revert
A variant of osm-revert, ohm-revert makes it easy to cleanly undo a changeset without opening JOSM. Despite the references to "OpenStreetMap" throughout, it uses your OHM credentials and affects OHM's database, not OSM's. Use this tool to combat vandalism or fix a messy mistake you made, but please exercise caution before undoing someone else’s good-faith edits.
Tagging conventions
- Main article: OpenHistoricalMap/Tags
OpenHistoricalMap tagging is largely based on as OpenStreetMap tagging with some significant differences to accommodate historical mapping.
Copyrights and licenses
- Main article: OpenHistoricalMap/Copyright
OHM is a bit different from OSM. Because of the differences, copying of data from OSM to OHM should NOT be done unless it can be determined that permissions are in place (e.g., if the author of the material can be identified and contacted to gain permission.)
OHM provides for mixed licenses using the license=*. Use of the CC0 license is preferred when sources allow. More information on CC0 may be found here.
Note on OSM derived data
As of June 2019, there is OSM-derived data in OHM and the markings on the OHM website are incorrect. The OHM community is working to address this.
Access from other projects
Many Wikipedia articles about places and events display geographical coordinates at the top-right corner. The coordinates link to the GeoHack tool, from which you can open the coordinates in a number of online map services, including OpenHistoricalMap.
Wikidata items can also link to OpenHistoricalMap via the OpenHistoricalMap relation ID (P8424) property, which is typically set to a chronology relation.
QLever can query OpenHistoricalMap and OpenStreetMap data simultaneously, making it easy to analyze relationships between the two databases (example).
Organization
OHM is in a state of transition. Since it started in 2012-13, it has been a fairly informal organization. It has become clear that a more formal structure is needed and OHM will be seeking to affiliate with a larger organization in the Open Source/Open Data community. In the meantime, folks involved in the informal organization are listening, and may be found in all of the communities listed in the next section. You find they are willing and eager to talk about where things are heading.
See also
- OpenHistoricalMap/Communication – get fast answers to your questions