Now called Old St. Mary's, this Gothic Revival structure is the oldest extant church in Fredericksburg. The stone exterior presents a heavy and somber appearance with no decorative carving of any kind. The massing of the tower is handsome, culminating in a beehive spire. The interior is austere, with every surface painted white.
By contrast, the new St. Mary's is more embellished both inside and out. Designed by Dielmann of San Antonio, it looks more French than German in terms of the delicacy of the details. The interior contains finely painted decoration of religious motifs and geometric details. Matching sets of confessionals, located across the nave from each other, are built into the side walls of the church and project on the exterior as three-sided bays with small lancet windows.