Open Historical Map (OHM) ( is an effort to use the OSM infrastructure as a foundation for creating the world's most universal, detailed, and out of date map. OHM will focus on the mapping elements where OSM excels - shores, political boundaries, buildings, and ways. Future and other efforts may engage in discussing actions, events, people, and movable items. is currently under maintenance, we hope to get it up before the end of April 2014.
Please poke Tim at if it isn't!
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More info about the project