Alpha Delta Theta used to be a national social sorority that was absorbed by Phi Mu in the late 1930s. At U of Illinois, during the depression, the sorority was forced to move into another sorority house, because ADT didn't own their house. So, they moved into the Phi Mu house, who at that time, was lacking membership. There's a sort of oral history on the UIUC website at:
http://web.library.uiuc.edu/ahx/slc/...oralhist5.html
They were also at Nebraska University...It was founded at Transylvania College in 1919 and had 9 active chapters. The Nebraska group was the Zeta Chapter. Here's a photo of their house from the 30s.
http://www.rootsweb.com/~neresour/OL...s/ch260222.htm
That's all I could find. Can you tell I do not want to do any more work?