In 1926, the Board of Trustees recognized the need for a larger library and assembly hall. A resolution was made to name the proposed building in memory of Amos Eaton. The library was built to accommodate 160,000 volumes and 240 readers. The auditorium could accommodate up to 1400 people. The building, another Lawlor & Haase design, was opened in 1928.

The library remained in Eaton Hall until it was moved to the former St. Joseph's Chapel in 1960. Auditorium space was eventually converted to lab, classroom and office space. Amos Eaton Hall was renovated in 1965 and currently houses the Department of Mathematical Sciences.