Later. Some revisions made.
There are two kinds of church with membership in the UUA that come across as odd to those unfamiliar with the concept: federated churches and multi-denominational community churches. Because they have multiple loyalties, they have a reputation to being aloof to denominations, making them that much less visible to those whose cares are more denominational.
Federated churches are communities of differentiated churches (they have their own membership rosters) that work together as a single congregation. Sometimes (but in practice, rarely) the constituent churches can be teased apart; sometimes they still have multiple buildings. (Which is why the United Church, Winchester, New Hampshire -- of Winchester Profession fame -- can sell its old Universalist building as the anchor for a new Universalist Heritage trail.) Because each constituent part has its own membership roster, there is almost always a majority and a minority party in federations. I'm sure this is stable in some places, but I can think of two federated churches that have dumped/lost/let-die-out its UCC and NACCC part respectively. But I'm guessing that Unitarians and Universalists are usually the one to loose because we don't produce enough (Christian) clergy to be viably settled in them. A bunch of these are at the bottom of the UUA size list, though this might not be obvious. First Universalist Church, Hiram, Maine looks like a tiny (five-member, tied for smallest with the UCC-federated First Church in Deerfield, Mass.) unfederated church, but its minister is the same as the thirty-five member NACCC-affiliated Hiram Community Church. And this is the part I love: the Universalist Church keeps its own post office box. Adam, can you explain this phenomenon?
Multi-denominational community churches -- as Adam also knows, as he pastors one -- are essentially single churches; one roster, one budget -- that's a member of two or more denominations. Some were formerly federated churches, though there was a time after WWII when new ecumenical new starts were planned to be multi-denominational (none surviving that I know of that were Universalist or Unitarian, except with each other.) Usually, for UUA purposes, the reported number is the denomination fraction of the total membership.
As far as I know, the denominations and fellowships with which there are federations or community church arrangements are:
- American Baptist Churches USA
- Christian Church (Disciples of Christ)
- National Association of Congregational Christian Churches
- United Church of Christ
- United Methodist Church
Did y'all expect that?