In 1960, together with Saul Weinberg, Thomas played an instrumental role in re-establishing the Department of Art History and Archaeology at the University of Missouri.

He played an important role in building the collections at Ellis Library, particularly with respect to archaeology and art history.

[2] Throughout his career, Thomas carried out important archaeological field work in Yugoslavia, Poland and Luxembourg.

A festschrift in his honor, Horizons and Styles: Studies in Early Art and Archeology in Honour of Professor Homer L. Thomas, was published in 1993.

[2] Thomas retired as Professor Emeritus in August 1984, after which he moved to the Washington metropolitan area.