St. John’s Chapel, to the right of the high altar, features an intricate reredos carved directly into the surface of the chapel wall — it took two craftsman three years to complete. The reredos depicts the Crucifixion, with St. Mary keeping vigil on the right and St. John, the beloved disciple, on the left of the cross.

A recessed area on the chapel’s south wall frames the tomb of Norman Prince (1887-1916), a young aviator and godfather of the U.S. Air Force. Prince distinguished himself in aerial combat over France in World War I and was a founding member of the Escadrille Americaine, a squadron of American pilots who flew as volunteers for France. Prince died following a failed landing attempt on Oct. 15, 1916. He was originally buried in France but was reinterred in the Cathedral in 1937 at the request of his parents, who were the benefactors for St. John’s Chapel.

Stained glass windows in the chapel depict the various miracles of Jesus as described in the Gospels.

The kneeler cushions depict famous Americans, including 39 (deceased) U.S. presidents. Symbols on each cushion represent the lives of men and women who contributed to American politics and culture, including Herman Melville (a ship, anchor and great white whale), John F. Kennedy (a rocket to symbolize the birth of the American space program) and Susan B. Anthony (a ballot box and a quill).