The main substance of this article is an extended review of a recent book by a Southern Baptist historical theologian, Malcolm Yarnell, entitled The Formation of Christian Doctrine, which aims to root the development of doctrine in a free-church ecclesiology. This review offers the opportunity to examine a spectrum of ecclesiologies that has recently emerged among Baptists in the Southern region of the United States of America. Four 'conservative' versions of ecclesiology are identified, which are named as 'Landmarkist', 'Reformed', 'Reformed-Ecumenical' and 'Conservative Localist'. Four 'moderate' versions are similarly identified, and named as 'Voluntarist', 'Catholic', 'Moderate Localist' and 'World-Baptist'. While these categories are not intended to be mutually exclusive, the typology is useful both in positioning Yarnell's particular thesis, and in making comparisons with recent Baptist ecclesiology in Great Britain, which has focussed on the concept of covenant. Yarnell's own appeal to covenant is unusual in Southern Baptist thinking, and means that he cannot be easily fitted into the typology suggested. Though he belongs most evidently to the group named here as 'Conservative Localists', and is overtly opposed to any concept of a visible, universal church except in an eschatological sense, it is suggested that his own arguments might be seen as tending towards a more 'universal' view of the reality of the church beyond its local manifestation. His own work thus offers the promise that present polarizations among Baptists in the southern United States might, in time, be overcome.