As World War I came to a close, a completely secret organization was founded on the rain soaked campus of the Case Institute of Technology. This Iroquois Club operated secretly until 1922 when it went public and rented its first home. With the house, the Iroquois society adopted the name Tau Gamma Psi and petitioned for membership in Phi Kappa Tau.

The request was rejected because the national fraternity was concentrating on expanding outside of Ohio. After much alumni lobbying, at the 1924 National Convention the petition was approved and Case became home to the Alpha Delta Chapter, the 28th chapter nationally and the fifth in Ohio. The first initiations were conducted by the Cleveland Alumni association on January 31, 1925. As chapter grew throughout the 20s and 30s, it frequently changed residences. In 1941, Alpha Delta purchased a house on the Abington Road fraternity row. This house was sold to the University in 1952, when the chapter purchased a luxurious home at 11318 Bellflower Road.

The house on Bellflower was home to the chapter until the Case Institute of Technology merged with Western Reserve University, and the fraternity acquired a modern four story residence on the south side of Campus, where the fraternity remained until it ceased operations in 1992.

In the fall of 1998, national expansion consultants Jeff Anderson and Carlos Salazar set about re-establishing a colony on campus. They enlisted the help of the fraternity's previous advisor Doctor Ocasio, and Beta Chapter alum Doug Brown to advise the colony they were forming. Eleven students, primarily freshmen, were associated on the eve of the Colonization, Thursday October 8, 1998. Shortly after the ceremony attended the forty or fifty person colonization banquet. The banquet was an affair which well exceeded the allotted budget, but introduced the Alpha Delta Colony in a style to be remembered.

The Colony became officially recognized by the campus Inter Fraternity Council on February 26th, when it presented itself to the IFC and representatives from the Panhellenic council and was conferred colony status by an IFC vote.

During the Spring of 2000, the National Fraternity accepted the colony's petition to be inducted as a full chapter. As a result, on May 11, 2000, staff from the National Fraternity along with brothers from the Baldwin-Wallace Chapter initiated 23 of the associate members over the course of 6 hours. The next day, May 12, 2000, the group was ceremoniously inducted as the Alpha Delta Chapter of the Phi Kappa Tau Fraternity. This took place during a large banquet which was attended by nearly the entire staff of the National Fraternity, parents, friends, and important CWRU staff, who all came to witness two years effort come to fruition.