Lysander Dudley had just completed his work at St. Francis Xavier Church when he began work on First Baptist, where he was a deacon and a member of the building committee. According to a sesquicentennial history of the church, he
The church is a good example of the pre-Richardsonian interpretation of Romanesque architecture known, from its German origins, as Rundbogenstil. Round-arched windows and doors, heavy lintels, and corbeled cornices are all salient characteristics of the style. The steeple is a 1973 aluminum copy of the original frame one, which was removed after being declared structurally unsafe. The auditorium has been remodeled several times over the years, and the Christian Education Building (William C. Dodd, architect) was added to the rear in 1958–1959.