Encyclopedias, Almanacs, Transcripts, and Maps
- Ateneo de la Juventud (Athenaeum of Youth)
- Ateneo del Uruguay
- Atheismusstreit
- Atkins, Robert Coleman
- Atkinson, Theodore Frederic (“Ted”)
- Atl, Dr. (1875–1964)
- Atlantic Islands, Migrants from
- Atomic Theory in Indian Philosophy
- Atoni
- Atrash, Sultan Pasha al-
- ATTRIBUTIVE NOUN
- Atusparia Revolt
- Atwater, Harvey Leroy (“Lee”)
- Aubrey, James Thomas, Jr.
- Auchmuty, Samuel (1758–1822)
- Audiencia
- Audiencia de los Confines
- Auerbach, Arnold ("Red")
- Augustine of Hippo 354–430 Bishop and Author
- Augustinianism