[HQWest]

Back in the day - in the south, some schools only begrudgingly gave in to legislators in allowing women in to campus. Sometimes this was done by limiting the classes they could take - but also in limiting their access to campus. In the early 20th century - it would not have been seemly for a young lady to live alone or in a boarding house. Schools avoided having to deal with coeds by not allowing for dormitories for women. A woman who wanted to attend would need to find a family member living nearby. Two groups stepped up to address this - sororities and the Scottish Rite. The origins of the southern manor sorority houses are in providing comparable safe housing.

ETA: I think that some of the origins of the emphasis on rec letters and knowing someone in the house already comes from feeling like new members would be new roommates. In the case of the old sleeping porches - this might be true for the whole chapter.