The design has been significantly altered over the years. The original design featured a 75-foot tower with spire and belfry. An apse was added in 1898 for the bodies of Henry Williams Sage and his wife. The mosaic decoration of the apse was created by J&amp;R Lamb Studios of New York; preliminary designs for this work can be found in the Lamb Studios Archive in the Library of Congress. A north transept was added in 1903. In 1940-41, a west wing expansion and renovation added more space for a new choir loft and the current pipe organ, a 3-manual Aeolian-Skinner with 69 stops and an estimated 3858 speaking pipes. The organ incorporates several ranks of pipes from previous instruments, including two of the previous organs built in the chapel. The building includes Tiffany glass windows and a stained glass memorial to three civil rights workers (one of whom was a Cornell alumnus, Michael Schwerner), murdered during Freedom Summer.