Casaday and his family filled the big, old house at 625 West Colfax Street with hundreds of thousands of items including, books, pamphlets, periodicals, recordings, sheet music, scripts and scores, art, programs, clippings, photographs, travel memorabilia, correspondence, and mementoes of all kinds. In addition, the Casaday costume collection at Central High School grew to thousands of items.
After Emma Casaday's and Ada Myer's deaths in the early 1970s, and his own retirement from the South Bend Schools in 1973, Casaday began to dispose of some of his massive collections. He gave part of the Costume Collection to the Northern Indiana Historical Society. Starting in 1972, he donated to the IUSB Library many of his books, scores, recordings, sheet music and programs. Acquisitions were overseen by Librarian (and later Dean of Library Services) Donna Harlan. Over the next 18 years, Casaday continued to donate items periodically. Many of the personal papers came in after Casaday's move an apartment in South Bend's North Shore Woods neighborhood in 1975, and some arrived after his death in 1990.
For convenience's sake, distinct collections have been created within the Casaday Theatre Collection, some to be treated as special collections, others archivally. The items inventoried here and considered archival include correspondence, photographs, family and history items, clippings, play production scrapbooks, posters, art, scripts and prompt books, original scores, programs of plays and operas in which Casaday was personally involved, and all sorts of other personal papers and artifacts.
The wide assortment of published plays and other books, periodicals, sheet music, published scores, and the large playbill collection (including hundreds of playbills from Chicago, New York, and other major city theaters) are treated as special collections. The books in these collections have been almost entirely catalogued. The periodicals, scores, sheet music, playbills and other items have been incompletely catalogued or (in some cases) not at all. The entire collection of sound recordings, except for just a few items, was sold by the Library in 1991.