The church was built in the English perpendicular gothic style, after plans approved by Ralph Adams Cram. The interior is noteworthy for its beautiful use of wood and its extensive stained glass windows, installed in a seventy year period between 1912 and 1982.

The windows are entirely in the medieval gothic style, using imported glass, executed by the Willet Studios of Philadelphia. The windows in the Chancel area are the themes from the Rosary; one of the few Episcopal churches in the United States using those images.

The carved reredos is the single most distinctive work of art in the sanctuary. It was carved from Black Forest walnut and installed in the 1920's by Alois Lang, a German woodcarver. Richly detailed with extensive Christian symbolism, the reredos is crowned by a Christus Rex, surrounded by statues of significant Biblical figures.

The high altar is built of Caen stone from quarries in France with a marble table piece. The altar was moved out from its original location to its current freestanding position in the 1970's.

A major refurbishing of the interior of the structure in 1990 resulted in newly carved wood canopies over the sedelia and the Bishop's throne. A cathedral gets its name from "cathedra" the seat or throne of the diocesan bishop. These are the work of the late Gordon Benson, master craftsman, a communicant of St. Paul's. Additional work to make the church building and the communion rail accessible to persons with disabilities was carried out in 1995.

Between 1999 and 2002 the Cathedral completed two major expansion projects that provided additional classroom and office space, a new atrium entrance area and a social space know as the Cafe', plus elevator access to all floors of the buildings.

(Information courtesy of the Episcopal Diocese of Springfield)