Interprets and maps aliquots of land patents in the Public Land Survey System

This takes historical data on federal land patents from the Bureau of Land Management Office to map the original purchasers of land. It also allows you to filter by year and see how the purchasing of land progressed over time.

See a live version here: https://clintonhistorymuseum.org/etc/patentplatter/

For a stripped down and rewritten version of the core functionality (but still without the bells and whistles), see: https://github.com/brsloan/patent-platter-SVG

• Accession: "IN1040__.020"
• Names: "ASHTON, ELIAKIM"
• Date: "11/1/1830"
• Doc: "8334"
• Twp_Rng: "022N - 001W"
• Aliquots: "E½SE¼"
• Sec: "25"
• County: "Clinton"

This tells us that Eliakim Ashton bought the eastern half of the southeastern quarter of section 25 of township 22 North, range 1 West. (For more on this Public Land Survey System, see here: https://en.wikipedia.org/wiki/Public_Land_Survey_System)

It interprets the aliquots to divide a grid of HTML divs into the appropriate plats and color/label them accordingly.

This is a messy system that does not separate logic and display very well, and since it is just a bunch of HTML divs you can't easily generate image files to download on the fly. Currently the "Download Map" link just goes to a subdirectory where, if I had uploaded them, would be a collection of premade image files corresponding to the different townships which I had made by printscreening the page. Not good. To fix this, I have created a separate SVG version that separates the logic entirely and generates an SVG graphic that can be created/downloaded on the fly. But I'm still fine tuning that. (If you'd like to see an example of the SVG generated map, see here: https://github.com/brsloan/patent-platter-SVG)

Also, obviously, this is only set up to work in a specific area, but you could easily adapt it to map patent data anywhere.

Some patents for irregular land masses (along a river, for instance) don't adhere to the strict aliquot format this can interpret, so they may not be mapped.

The BLM data does not appear to be super clean, as I have come across quite a few transcription errors and had to go look at the scans of the original handwritten patents to correct them (not that I'm complaining--what an amazing resource they have given us with this). As a result, there are sometimes two conflicting patents--either they overlap or both cover the same land. In these cases, it flags them by highlighting them red both on the map and in the index. This you can use as an indicator to go back and examine the patents to find the mistake and correct the transcription.