The Zimmerman Law Library opened as the University of Dayton Law Library in 1974 with the re-establishment of the School of Law. The first director of the library, Oscar Trelles, along with acquisitions librarian Theodora Artz, started the law library collection, which shared quarters with the rest of the school on the ground floor of the Roesch Library. After acquiring renovated space in Albert Emmanuel Hall in the mid-1970s, the majority of the law school moved out of Roesch. The law library remained in the building, connected to Albert Emmanuel by an enclosed but dimly-lit and poorly heated “tunnel.”

By the early 1980s, the library had signed on with Mead Data Central (now LexisNexis) and had one Lexis terminal. Much of the initial content of the Mead Data Central database was gleaned from the public domain materials in the collection of the University of Dayton Law Library. A subscription to Westlaw followed in the mid 1980s.

Planning for a new unified law school/law library under one roof proceeded in earnest in the early 1990s. Joseph E. Keller Hall opened in July 1997, and the University of Dayton Law Library was renamed the Dr. J. Milton and Doris Zimmerman Law Library, in recognition of substantial support given to the law school building fund by Mrs. Doris Zimmerman.

The Zimmerman Law Library occupies one-half of the second floor, most of the third floor, and a small portion of the fourth floor of Joseph E. Keller Hall. The 46,130 square foot space holds more than 295,000 volumes, including more than 133,000 volume equivalents of microforms. There are 501 seats, all of which have access to wireless data and power, and the library is open 102 hours per week during the regular semester.