The chief characteristic of the Romanesque Revival style is the semicircular arch, used for window and door openings as well as a decorative element along the corbel table. Other characteristics include an archivolt of compound arches and square towers of different heights and various roof shapes. A crenellated tower parapet is common. The Romanesque Revival style, exemplified by St. Anthony’s Church in Sterling, is found mainly on churches and large institutional buildings.
Richardsonian Romanesque, named after architect Henry Hobson Richardson (1838-1886), is characterized by heavy, rock-faced stone, round masonry arches, contrasting colors, transom windows arranged in ribbon-like patterns, square towers, and sparse fenestration. The Pueblo Union Depot is as similar to Richardson's work as any structure in Colorado, and yet, is not a pure example. Most of the Richardsonian Romanesque structures are variations of the style, employing selected Richardsonian elements.