Horace Holley was for more than thirty years Secretary of the National Spiritual Assembly of the Bahá'ís of the United States (and until 1948, of Canada), and was also widely known as an editor, writer and teacher. In 1951 he was elevated by the Guardian of the Bahá'í Faith to the rank of a Hand of the Cause of God, and in this capacity he travelled throughout the Western hemisphere, as well as to other continents, to stimulate and guide Bahá'í activity. In 1959 he was called to serve at the Bahá'í World Centre of the Faith in Haifa (Israel) where, in 1960 he died, and is now buried on Mt. Carmel.

Mr Holley's was a unique contribution to the establishment of the world-wide Bahá'í Administrative Order. His writings are unexcelled in this field and were highly esteemed by the Guardian, Shoghi Effendi, who wrote: 'I greatly value your presentation of the various aspects of the Cause, for whose expansion, consolidation and defence you have, for so many years, laboured so indefatigably and served with such distinction'.