Ethical Culture is small, and has been for a long time. The best-supported figure is fewer than ten thousand formal members across roughly thirty societies, dating from 2014; more than a decade on, that remains the most recent reliable count available rather than a current one.
The societies are concentrated in the north-eastern United States, with the New York society, its landmark meeting house on Central Park West, and the Fieldston School as the movement's most visible institutions. The American Ethical Union, formed in 1893 when the first four societies federated, remains the national body. Sister organisations founded in Britain and Germany in the 1880s and 1890s took different paths, and the British line fed into what became that country's humanist movement rather than persisting as ethical societies.
The movement's difficulty is partly of its own making, and it knows it. Organised humanism, which Ethical Culture helped to create and which it joined as a constituent body, offers the same convictions without the Sunday meeting, the Leaders and the congregational form, and most people who share the convictions have taken the version with fewer obligations. A body that exists to supply religious community to people who do not want religion is competing against the option of simply not attending.
What it retains is a demonstrated answer to a question that recurs constantly and is usually asked rhetorically: whether the practices of religious community (weekly gathering, the moral education of children, rites for birth, marriage and death, organised charitable work), can survive the removal of the theology. In one city, for a century and a half, they have.