After the Civil War, it became the custom of graduating classes to plant a young tree on the Hill and place before it a stone to memorialize the class on its class day. The plaques marking the class trees of 1877, 1879, 1881, and 1882 remain on the Hill in front of Ayres Hall. Classes also provided memorials in the form of gifts to the institution, such as the marble bench in the shape of a T commemorating the senior class of 1921.
Other class memorials include the following: Class of 1900—Sun dial in front of Science Hall; Class of 1913—Marble drinking fountain in the entrance of Science Hall; Class of 1914—Clocks in Science Hall Chapel and Carnegie Library; Class of 1915—New pulpit in the Science Hall Chapel and trophy case to be placed in the Carnegie Library Auditorium; Class of 1916—Two iron benches on the campus near Science Hall; Class of 1917—Trophy cabinet for the president’s office; Class of 1918—Permanent flag pole for the Hill; Class of 1919—Oil portrait of Dr. Brown Ayres, and planting ivy alongside Ayres Hall as the beginning of a tradition (Planting ivy at Ayres was nixed by the university in 1922 because better brick had been used in the construction of Ayres than in Science Hall; therefore, vines were not needed and might affect the mortar.); Class of 1920—Bronze bulletin boards for Ayres Hall; Class of 1922—Loan fund; Class of 1925—Steam whistle for the new power plant (now Pasqua Nuclear Engineering), which marked the beginning of each class period with three sharp blasts; Class of 1931—Clocks for the clock faces on Ayres tower; Class of 1933—Establishment of an alumni foundation; Classes of 1963–64—Library Endowment. (Dr. John Hodges announced that he would obtain a matching contribution for every dollar to the library endowment contributed by the graduating senior class of 1964.) In 1991 the Development and Alumni Affairs Offices began a formal program of senior class gifts.