As of 2000, the largest number of religious adherents in Washington, D.C., were Roman Catholic, with about 160,048 adherents in 42 congregations. Mainline Protestants were next in numbers with the American Baptist Churches in the USA claiming 51,836 adherents in 62 congregations and the Episcopal Church claiming 19,698 adherents in 34 congregations. The Southern Baptist Convention had 38,852 adherents in about 49 congregations. The Jewish population was estimated at 25,500. About 26.8% of the population were not counted as members of any religious organization.
The Washington National Cathedral was established by Congress through an 1893 charter with the Protestant Episcopal Cathedral Foundation. The charter was signed by President Benjamin Harrison. The building was completed in 1912.