The University photographs depict the lives and activities of the students, staff, and alumni of the University of Dayton and illustrate the functions of the University, including classroom instruction and laboratory research. The photographs date from the late 1890s to the present, documenting the evolution of St. Mary's Institute, a small, private grammar school for boys, into a well-known Catholic and Marianist institution of higher education and research. The school changed names several times between its founding in 1850 and 1920, when it was renamed the University of Dayton.