Microproduct data guideintermediate

Census TIGER/Line Boundaries

Official U.S. geographic boundaries and feature codes for building maps, spatial joins, service-area analyses, and demographic products.

Start the guide Open official source

At a glance

Difficulty
Intermediate — some data preparation helps
Size
Medium · 0.001–1 GB
Formats
Shapefile, GeoPackage, ZIP
Access
Download
API key
Not required
Provider
U.S. Census Bureau
Updates
Annual
Data terms
U.S. Government public data / federal copyright guidance

From source to product signal

Test a product idea in four steps

TIGER/Line files provide official geographic boundaries and identifiers that join to Census statistics. Start with the national county file for one pinned vintage and one ACS variable. Boundaries change over time, and the geometry files contain no demographic measurements themselves.

1

Check the setup

  • Python 3.10 or newer
  • A notebook environment such as Jupyter or Google Colab
  • Enough memory for one national county boundary file
2

Access the data

  1. 1.Choose a TIGER/Line vintage that matches the statistical data being joined.
  2. 2.Download the national county ZIP and read only the columns needed for the map.
  3. 3.Join on full Census geographic identifiers rather than names.
Open official source
3

Run the Python example

Install the packages, then run the notebook cell.

python -m pip install geopandas pandas

import geopandas as gpd
import pandas as pd

counties = gpd.read_file(
    "https://www2.census.gov/geo/tiger/TIGER2025/COUNTY/tl_2025_us_county.zip"
)[["GEOID", "NAME", "STATEFP", "geometry"]]
california = counties[counties["STATEFP"] == "06"].copy()
california["retrieved_at_utc"] = pd.Timestamp.now(tz="UTC")
print(california[["GEOID", "NAME"]].head(20))
4

Test a useful signal

Prepare county boundaries for an ACS map

Create a California county layer that can join safely to ACS five-year estimates.

  1. 01Read the pinned county vintage and retain GEOID values as strings.
  2. 02Filter to California and verify that geographic identifiers are unique before joining ACS data.
  3. 03Explain how boundary vintage, geometry simplification, and missing demographics limit the layer.

Dataset details

U.S. Census Bureau is a government source. Last verified 2026-08-13. Temporal coverage: annual boundary vintages from 2007-present.

Theme

Geospatial & Infrastructure

Domains

GeographyCensus Geography

Data types

GeospatialVector Data

Tasks

GISSpatial JoinMapping

Geography

United States

Formats

ShapefileGeoPackageZIP

Provider

U.S. Census Bureau

Data terms

U.S. Government public data / federal copyright guidance