The church moved uptown to its new building in 1859. To support the weight of the huge central spire (completed in 1874), the architects designed massive stone piers with cast-iron columnns at their centers. These columnns were a marvel of engineering, as one historian wrote. A contemporary observer described them as the most massive and scientifically arranged cast iron framework ever done in this country or in any other.
Adjoining the church is a building known as the Manse or the Backus House; it was the residence of the Rev. John C. Backus, who organized the relocation of the church. In 1861, Backus was instrumental in the passage of the controversial Gardiner Spring Resolutions, which, in the patriotic fervor surrounding the opening of the Civil War, required pastors to swear allegiance to the federal government.