The limestone National City Christian Church was erected at a cost of $1.2 millon as the mother church for the Church of the Disciples of Christ. John Russell Pope designed its Ionic portico surmounted by a 164-foot tower (from the portico's stylobate) as a twentieth-century reinterpretation and refinement of English Baroque churches. He was particularly influenced by James Gibbs's Saint Martin-in-the-Fields (1722–1726) in London, which had provided the model for numerous eighteenth- and early nineteenth-century American churches. Pope commonly choose such familiar architectural prototypes, subtly transforming them by passing them through his exceptional intellectual and visual process of simplification. He probably consulted Gibbs's A Book of Architecture (1728), in which Saint Martin's as built was illustrated in addition to an alternate design. Pope's hexastyle portico is Ionic while Gibbs's is Corinthian, but Pope passes his square tower through a secondary pediment set above and behind the entry portico, a motif common in the Baroque architectural tradition but not used by Gibbs at Saint Martin's. One distinctive change was setting the National City Christian Church upon a high podium entered by a broad and long flight of stairs. For the lower two stages of his spire, Pope followed the Gibbs prototype with only minor alterations, adding quoins to the corners of the tower as it emerges from the roof and framing the arched opening above with single engaged Ionic columns rather than Gibbs's double Ionic pilasters. For the third stage, where the transition from square to circular begins, Pope used Gibbs's alternate, unbuilt Saint Martin's tower design, which had a more sculpturally elaborate scrolled frame for its circular clock, replaced by Pope with a blank panel. Gibbs's tower terminated in a tall spire, while Pope designed a circular Corinthian tholos topped by a small rotunda and dome to complete his composition. Gibbs's pointed spire may have suggested medieval architectural form to Pope, who probably found the fusion of medieval and classical vocabularies totally inadmissible. Pope was not averse to medieval architecture; when the church committee was undecided between a Neo-Gothic and a Neoclassical church, he provided sketches in both styles. However, his sense of the correctness and purity of architectural traditions was contrary to the kind of eclecticism that borrowed indiscriminately.