What's the largest church in your county?

Name: America's churches, county by county: the largest church and the share of residents on church rolls
Creator: Landscript

Type your county or click the map. Every county is colored by its largest church, from the 2020 U.S. Religion Census.

America's churches, county by county

The U.S. Census Bureau doesn't count religion, so the most complete county-by-county count of American congregations comes from the churches themselves. Every ten years the Association of Statisticians of American Religious Bodies asks every denomination it can reach to count its congregations and members in every county. In 2020, about 48.6% of all Americans were on the rolls of a church, temple or mosque. The Catholic Church is the largest church in 1,231 counties, and the Southern Baptist Convention in 1,056, most of them in the South.

Highest share of Southern Baptists

Highest share of Catholics

Highest share of Latter-day Saints

Lowest share on any church roll

Lists: counties with at least 10,000 residents, share of all residents on the rolls of that church. Counties where church rolls add up to more than the population are left out.

Questions and answers

What does this map count?: Church rolls, not beliefs. The 2020 U.S. Religion Census counts “adherents” reported by congregations: members, their children and others who regularly take part. They are counted where the congregation is, not where people live.
Why are some counties above 100%?: Because people are counted where their church is. If a big church draws people from neighboring counties, a small county can end up with more people on church rolls than residents. That happens in about 30 small counties.
Why doesn't the census ask about religion?: Since 1976, federal law (13 U.S.C. § 221) says nobody can be compelled to disclose their religious beliefs or church membership to the census. From 1906 to 1936 the Census Bureau ran a separate census of churches every ten years; the one planned for 1946 was never finished.
Why is so much of the South red?: Red is the Southern Baptist Convention, the largest church across most of the South. Historically Black denominations are undercounted in the 2020 data, so in parts of the Deep South the Southern Baptist lead is overstated.
What about Connecticut?: In 2022 Connecticut replaced its counties with planning regions, but the 2020 religion census uses the old counties. Each region is shown with the numbers of the old county most of its people come from.
Where is the data from?: 2020 U.S. Religion Census: Religious Congregations & Adherents Study (Association of Statisticians of American Religious Bodies, 2022; data files updated June 23, 2023), usreligioncensus.org. Population: U.S. Census Bureau, 2020 Census. County boundaries: U.S. Census Bureau, Cartographic Boundary Files 2025. Shares are our calculations.

The religion census data belongs to its authors (ASARB). If you use numbers from this map, please cite the 2020 U.S. Religion Census.