Starting in 1921, BSA councils were organized into twelve regions that roughly corresponded to the twelve districts of the Federal Reserve banking system. As part of the 1948 integration into the BSA program, the 26 OA areas were abandoned and lodges were redistributed among the twelve scouting regions. Each region was further subdivided into areas, in which lodges participated in annual training conferences.
The September National OA Bulletin, as shown in "OA AREAS as of September 1948" (Dingwerth appendix 6), lists 28 areas that lodges were initially assigned to. However, some regions underwent changes before the first conferences were held in 1949, including Region 2 and Region 6.
The Twelve Regions lasted from 1949-1972. The 1973 New Section Operation created six regions: Northeast, East Central, North Central, Southeast.
