thfield
commented
7 years ago to get the topojson file of Zip codes here, i used the makefile (tutorial) attached.
(disclaimer: i might have an older version of cli topojson on my computer, so i would recommend following this tutorial up through creating geoJSON files)
the census might publish a shapefile for congressional district, or you might be able to find one from another source.
if you're looking for topoJSON files of counties or states, check out us-atlas
Makefile:
cb_2016_us_zcta510_500k.zip:
curl -O 'http://www2.census.gov/geo/tiger/GENZ2016/shp/cb_2016_us_zcta510_500k.zip'
cb_2016_us_zcta510_500k/cb_2016_us_zcta510_500k.shp: cb_2016_us_zcta510_500k.zip
unzip cb_2016_us_zcta510_500k.zip
touch cb_2016_us_zcta510_500k.shp
zipcodes.json: cb_2016_us_zcta510_500k/cb_2016_us_zcta510_500k.shp
topojson -o zipcodes.json -- zipcodes=cb_2016_us_zcta510_500k.shp
us.json:
curl -Lo us.json 'https://unpkg.com/us-atlas@latest/us/10m.json'
ca.json: us.json
mapshaper us.json \
-filter 'FID === "06"' target=states \
-o ca.json format=topojson target=states
# ca_zips.geojson manually created using QGIS to clip zipcodes.json using the boundaries of ca.json
ca_zips.json: ca_zips.geojson
mapshaper ca_zips.geojson \
-simplify 20% \
-o format=topojson
ca_zips_simple.json: ca_zips.json
topojson -o ca_zips_simple.json -p GEOID10 -- ca_zips.json
Iterations on Map layers will use congressional districts and county levels. Let's find those GeoJSON files.