The celebration of Class Day in association with Commencement occurred for the first time in 1855. Established to call attention to the accomplishments of the graduating class and to emphasize the lasting bonds of friendship, Class Day gradually came to include a variety of activities ranging from the semi-serious and nostalgic to the fanciful and humorous. Music, orations, and poems composed for the occasion as well as class chronicles (histories) and prophecies proved extremely popular as did the presentation in the early years of a gift to James Williams, known affectionately as Professor Jim, the College"s first general factotum, who served from 1830 to 1874. Born a slave, he had become a free man, and after extensive travel came to Hartford in the employ of the Rt. Rev. Thomas C. Brownell, Trinity's principal founder and first president. Professor Jim bade the seniors farewell in brief remarks at Class Day and served them punch. From the implement he used to prepare the punch emerged the tradition of the "Lemon Squeezer," which is discussed separately.

Class Day also was the occasion for the planting of the class ivy, which first occurred in 1851. That year, a freshman, Edward B. Hughes of New Haven, Class of 1855, brought ivy plantings to the Old Campus, obtained from sprigs at Trinity Church, New Haven. By 1872, the class ivies covered the walls of Jarvis and Brownell Halls, the dormitories. On the Summit Campus, ivy planting gave way for a brief period to the planting of class elm trees.

In addition, it became customary on Class Day to present athletic awards and to hold a dance, for which elaborate programs were printed. Formal invitations were sent to family and friends, and dance cards with pencils attached were prepared for recording the names of dance partners. By the post-World War II period, the proceedings had expanded to include a guest speaker, often a parent. For example, in 1962, Professor Frederick L. Will spoke to the seniors. Chairman of the Philosophy Department at the University of Illinois, Will was the father of George F. Will, the future Pulitzer Prize-winning columnist and political commentator.

A time-honored custom associated with Class Day was the ceremonial smoking of the "pipe of peace," instituted in 1856 as a symbol of friendship. The earliest known photographs of Class Day are from the World War I period and show the seniors seated while smoking their pipes. The chairs were set up on the Quad in front of Northam Towers, the prevailing location for Class Day on the Summit Campus, weather permitting. Parents and guests sat behind the graduating class during the ceremonies, and watched as each senior puffed his long-stemmed clay church-warden pipe that he had filled from a large tobacco box available for the occasion. In later years, seniors smoked their pipes during the procession of the graduating class down the Long Walk to Northam.

A long-lived tradition, Class Day served to foster spirit and group identity among the members of each graduating class, and was looked upon as an occasion for reflection about four years " 'Neath the Elms." Celebrated until 1968, Class Day was discontinued with the advent of
coeducation, but was revived in 1999.