Description: ATO Congress Subject File (1870-), including correspondence, programs, publicity, planning materials, and copies of the Palm Junior, a newsletter published during Congresses. Congresses were held biennially 1870-1972 (an extra Congress was held in 1877; no Congresses were held between 1941 and 1956); annually 1972-90, and biennially thereafter. This series includes materials relating to proposed special Congresses, which were never held in 1965 and 1969. It contains materials concerning Chapter Officers' Leadership Conferences when these were combined with Congresses.