Reading though Russell Miller’s The Larger Hope I came across these sentence about the Philadelphia Convention, which I’m reading about now.
Universalist societies in fellowship between 1790 and 1809 were small, weak, and lacked financial resources. With the exception of the Philadelphia church, the largest had only fifteen members and one only had six. (vol. 1; p. 79, citing Richard Eddy, Universalism in America, vol 2, p. 122.)