The early history of the Hamilton Chapter is the early history of the Fraternity. From an original letter written by Samuel Eells, HAM 1832, donated to the Fraternity archives by Samuel Eells Jr., WMS 1957, we now know the exact circumstances of the founding of the Hamilton Chapter, and thus, the Alpha Delta Phi.

"…on the part of the delegates from Union, and but few students of Hamilton were consulted on the subject. I was one of those spoken to, and I at once saw that it would interfere with my scheme. I found it necessary, therefore, to make a show of hesitation with regard to the proposition, that I might if possible devise some way of defeating it. Most of those to whom the plan of the Kappa Alphas was disclosed received it with favor, but in a small private meeting held for deliberation and organization, means were found of dividing our counsels. The whole project was abandoned, and the delegates withdrew, disappointed and chagrinned. Immediately after this occurrence, I resolved to commence the trial of the new society. The first step was to select a very few of the most influential members of each literary society, to open to them cautiously one by one, the outlines of my plan, and enlist their cooperation. The individuals whom I pitched upon were, out of the Phoenix Society, three, viz. Lorenzo Latham, Oliver Morse, and Henry L. Storrs; and of my own society, two, viz. Brewster and John C. Underwood. To my surprise, all without hesitation approved the plan, and engaged in the undertaking with the utmost ardor. Secretly, and without any formal meeting, we pledged ourselves to the work. The first meeting was held at my room, No. 15 back-middle Kirkland Hall. All the persons above named were, I believe, present; but as it was only a meeting for consultation, no presiding officer was appointed, and no minutes were taken. After this meeting, and before any steps towards a farther organization, we were surprised by the appearance of some eight or ten students decked with the badge of Sigma Phi. It seems that the members of that Society at Union College, apprized of the failure of Kappa Alpha, were induced to make an experiment of their own success. They consummated the formation of a society, and to our regret, took one of our members, Waire W. Brewster, a most noble and estimable fellow, and a fine scholar. He had supposed that as we did not go into operation immediately, we had abandoned our project. That he was greatly disappointed in the Sigma Phi Society, I have every reason to believe, and I think he never put on the badge. He was in possession of none of our secrets, except the bare fact of our intention to establish a new society, for good care was taken to suppress the unimportant details of the system till every member should be irrevocably engaged. Immediately after this establishment of the Sigma Phi, we came together again, and appointed a committee to report a constitution and badge. The committee consisted of Lorenzo Latham and myself; and the whole constitution and covenant were prepared by myself. "

The original five founders, Samuel Eells, who died in Cincinnati in 1842, Lorenzo Latham, who died in New Orleans in 1860, Henry Lemuel Storrs, who died in 1852, Oliver Andrew Morse, who died in 1870, and John C. Underwood, who died in 1876, had given birth to one of the most pre-eminent fraternities in history. As written, it is without a doubt that Brother Eells was the one who exercised the controlling influence in the small group.

As the Chapter, and Fraternity, started to flourish, finances were acquired to erect a permanent home for the Hamilton Chapter. In 1882, the Chapter erected the "Samuel Eells Memorial Hall”, a stone building, in honor of the founder, which served as the hall of the Chapter until June 1928, when construction began on a new home. The new chapter house, also known as the "Samuel Eells Memorial Hall”, was completed and first occupied in the fall of 1929. At that time the remains of Samuel Eells were removed to the Samuel Eells Memorial Hall.

In September 1932, the mother Chapter acted as host to the other chapters at the Centenary of the founding of the Fraternity.

In December 1963 the mother Chapter conducted the installation ceremonies of the Madison Chapter at Colgate University, at which time the Samuel Eells award was presented to Grant Keehn, HAM 1921, President of the Equitable Life Assurance Society and Chairman of the Board of Trustees of Hamilton College.

In 1995 the College Board of Trustees passed the Residential Life Initiative, effectively ripping fraternities out of their homes at the school. In 1999, with much sadness and regret, the Chapter sold the beloved Samuel Eells Memorial Hall to Hamilton College. Samuel Eells was re-interred in the Hamilton College Cemetery. The small Chapter he helped found still remains at Hamilton College, and is still the Mother Chapter to the Alpha Delta Phi.