For several years, Doonan promoted the idea that a celebration of the university's centenary be organized, which culminated in an official celebration in February 1889. In anticipation of the occasion, in 1885, Doonan purchased two cannons in St. Inigoes, Maryland, for $50. The cannons had been brought to America aboard the Ark and the Dove, which carried the first settlers to the Province of Maryland as part of Lord Baltimore's 1634 expedition to St. Mary's County. Doonan had them placed in front of Healy Hall on November 1, 1888. He also proposed that Healy Hall's main auditorium, which remained unfinished, be completed and named Gaston Memorial Hall after the school's first student, William Gaston.
