A powerful tool that combines census tract data with demographic information and legislative districts to create rich, insightful geospatial visualizations.

Census Map Maker helps you create detailed visualizations by merging:

• Census tract boundaries
• Demographic data from the American Community Survey (ACS)
• Legislative district boundaries (senate, house, etc.)

This allows for powerful analysis of population distribution, demographic patterns, and how they relate to electoral districts.

• Add support for multiple demographic files at once
• Add more configuration options

• Node.js (version 14+)
• pnpm package manager
• Basic understanding of GeoJSON data

Download from the U.S. Census Bureau:

• URL: https://www.census.gov/cgi-bin/geo/shapefiles/index.php
• Select the year of data you need
• Choose "Census Tracts" as the layer type
• Select your state of interest
• Save as CENSUS_TRACTS.zip in the data/prepare folder

Download from the Census Bureau's data portal:

• URL: https://data.census.gov/table/ACSDP5Y2022.DP05?q=Age+and+Sex
• Important: Use the same year as your Census Tract data
• Must use a 5-year ACS (American Community Survey) dataset
• Configuration steps:
  1. Under "Geos" select: Census Tracts → [YOUR STATE] → "All Census Tracts within [STATE]"
  2. Click "More Tools" → "ZIP"
  3. Find the "ACS 5-Year Estimates Data Profiles" row
  4. Select the column matching your year
• Save as DEMOGRAPHICS.csv in the data/prepare folder

• Source varies by state (typically from state redistricting commission or secretary of state)
• Example for Florida: https://www.flsenate.gov/Session/Redistricting/MapsAndStats
• Save as DISTRICTS.json in the data/start folder

data/
├── prepare/             # Place input files here
│   ├── CENSUS_TRACTS.zip
│   └── DEMOGRAPHICS.csv
├── start/               # District data and processed files
│   └── DISTRICTS.json
└── examples/            # Reference data samples

Run the data preparation script:

pnpm prepare

This will:

• Extract and process census tract boundaries
• Merge demographic data with census tracts
• Generate POPULATED_CENSUS_TRACTS.json

Note: The script may report that 1-2 records couldn't be joined. This is normal and usually refers to CSV headers that can be safely ignored.

Run the main processing script:

pnpm start

This script will:

• Merge the populated census tracts with district boundaries
• Generate the final GeoJSON output file

Note: This process may take some time depending on the amount of polygon coordinates in your data.

The repository includes example data in the /data/examples folder to help you understand the expected format and structure of input and output files.

Once processing is complete, you can visualize the resulting GeoJSON using Mapshaper.org

Contributions, issues, and feature requests are welcome! Feel free to check the issues page.

MIT License