1) download census block shapefile- https://www.census.gov/cgi-bin/geo/shapefiles/index.php 2) import shapefile into mapshaper- https://mapshaper.org/ 3) export file as topojson (which is a condensed geojson file format) 4) upload topojson to github gist- https://gist.github.com/

shapefile saved here

put test point on the map

these are my census blocks in an array

loop through all blocks to find where the points are using the d3 geoContains function (https://github.com/d3/d3-geo) when finds it returns the census block

test returning name