In a classic essay on “Denominationalism,” Sidney E. Mead observed that “[t]he denomination, unlike the traditional forms of the church, is not primarily confessional, and it is certainly not territorial. Rather it is purposive.” When Mead published that in 1954, he was commenting on Protestantism, but in American censuses, registries, and common-sense observation, all religious bodies are considered denominational now. Still, most of these consider themselves to be in some sense “confessional,” and all tend to be more at home in some parts of the country than in other “territories.”