(RNS) — Montgomery County, Maryland, a Washington suburb, was the most religiously diverse county in the U.S. last year, according to a census released Thursday (Aug. 29) by the Public Religion Research Institute.

When PRRI did a similar study in 2020, Montgomery County came in third behind the New York City boroughs of Brooklyn and Queens. In 2023 those boroughs were relegated to second and 10th, respectively.

PRRI’s Census of American Religion, which focuses on U.S. adults age 18 and over, calculates religious diversity by analyzing 18 different religious and racial groups in counties with more than 10,000 residents. 

In the index used to rank counties, 1 signifies complete diversity, where every religious group is of equal size, whereas 0 signifies a homogenous religious population. Montgomery County received a score of 0.886.

Montgomery County, with a population of more than a million, is significantly more educated and wealthier than the U.S. average. One in six county residents has a bachelor’s degree or higher, and the median household income is $118,323. Voters go heavily blue, with 78.6% having supported Joe Biden in the 2020 presidential election.

The county is home to many federal government agencies, including the National Institutes of Health, the U.S. Food and Drug Administration and Walter Reed Military Medical Center and Army Institute of Research. It is also home to at least one Supreme Court justice, Brett Kavanaugh.

Only 56.8% of county residents speak English at home, with Spanish (17.2%), other Indo-European languages (10.3%) and Asian and Pacific Island languages (9.8%) most commonly spoken.

Beyond the religiously unaffiliated, who represent slightly less than 2 in 10 (17.8%) residents, the largest religious group in the county was Black Protestants, who make up 10% of the population. 

Christians overall made up about 60% of the population, with other large Christian groups including white mainline/non-evangelical Protestants (9.6%), Hispanic Catholics (7.7%), white Catholics (7.4%), Hispanic Protestants (6.9%) and white evangelical Protestants (5.4%).

In most of the top-10 religiously diverse counties, the religious groups with the greatest representation are the religiously unaffiliated, but in Nassau County, New York (20.6%) and Montgomery County, Pennsylvania (19.8%), white Catholics were the largest religious group. Nassau County, part of Long Island, came in third, and Montgomery County, a Philadelphia suburb, came in fourth.

Montgomery County, Maryland, the most religiously diverse county, was among the top 10 counties in the country with the highest concentration of several minority religious groups. It has:

• the second-highest concentration of Orthodox Christians, who make up 2% of the population;
• the third-highest concentration of Hindus, who make up 2.7% of the population;
• the fourth-highest concentration of Jews, who make up 9.3% of the population;
• the fourth-highest concentration of Muslims, who make up 3.2% of the population;
• the fifth-highest concentration of Buddhists, who make up 2.7% of the population;
• and the fifth-highest concentration of Unitarian Universalists, who make up 1.3% of the population.

While PRRI does not separate Seventh-day Adventists as one of their 18 religious categories, the group has a significant presence in Montgomery County. The county is home to Washington Adventist University, and Adventist HealthCare is a major employer in the county.

Throughout 2023, the county experienced religious conflict related to LGBTQ+ learning content in the public school system. 

In May of that year, Muslim, Catholic and Orthodox Christian parents began a legal challenge to the public school system’s decision to prohibit parents from opting their children out of lessons on books with LGBTQ+ characters, a decision also opposed by Moms for Liberty, the Council on American-Islamic Relations and Montgomery County Muslim Council.

So far, both a U.S. District Court judge and the 4th U.S. Circuit Court of Appeals have dismissed the request. The Becket Fund For Religious Liberty, which is representing the plaintiffs, has indicated that it intends to appeal the ruling.

In December 2023, a Muslim middle-school teacher in the public school system also filed a religious discrimination complaint with the Equal Employment Opportunity Commission after she was placed on administrative leave because of her use of “From the river to the sea, Palestine will be free” in her email signature.

The Council on American-Islamic Relations (CAIR) Legal Defense Fund is supporting her complaint.