This library contains boundaries published by the U.S. Census Bureau. All boundaries available at 1:500,000 resolution have been aggregated by type, quantized (to 100000), and converted into TopoJSON files, with all properties omitted (save for the GEOID property, which is added as the id for each geometry).

Since all files are already in JSON format, you just need to require them as follows:

let topology = require(`census-topologies/types/${NAME}`)

where NAME is one of the following:

• aiannh (American Indian Areas/Alaska Native Areas/Hawaiian Home Land)
• anrc (Alaska Native Regional Corporation)
• bg (Block Group)
• cbsa (Metropolitan Statistical Area / Micropolitan Statistical Area)
• cd114 (Congressional District)
• concity (Consolidated City)
• county_within_cd114 (County Within Congressional District)
• county_within_ua (County Within Urban Area)
• county (County)
• cousub (County Subdivision)
• csa (Combined Statistical Area)
• division (Division)
• necta (New England City and Town Area)
• place (Place)
• puma10 (Public Use Microdata Area (PUMA))
• region (National Region (Northeast, Southeast, Midwest and West))
• sldl (tate Legislative District - Lower Chamber)
• sldu (State Legislative District - Upper Chamber)
• state (State and Equivalent)
• subbarrio (SubMinor Civil Division (Subbarios in Puerto Rico))
• tract (Census Tract)
• ua10 (Urban Area/Urban Cluster)
• zcta510 (5-Digit ZIP Code Tabulation Area)