On the first evening of the convention a sermon was preached by Dr. James Freeman Clarke that was a noble and generous introduction to its deliberations. He called for the exercise of the spirit of inclusiveness, a broad and tolerant catholicity, and union on the basis of the work to be done. On the morning of April 5, 1865, at eleven o'clock, the convention met for the transaction of business in All Souls' Church, of which Henry Whitney Bellows was the minister. Hon. John A. Andrew, then the governor of Massachusetts, was elected to preside over the convention; and among the vice-presidents were William Cullen Bryant, Rev. John Gorham Palfrey, Hon. Ebenezer Rockwood Hoar, Rev. Orville Dewey, and Rev. Ezra Stiles Gannett, while Rev. Edward Everett Hale was made the secretary. In Governor Andrew the convention had as its presiding officer a man of a broad and generous spirit, who was insistent that the main purpose of the meeting should be kept always steadily in view, and yet that all the members and all the varying opinions should have just recognition. In a large degree the success of the convention was due to his catholicity and to his skill in reconciling opposing interests.
The time of the convention was devoted almost wholly to legislating for the denomination and to planning for its future work. On the morning of the second day the subject of organization came up for consideration, and the committee selected for that purpose presented a constitution providing for a National Conference that should meet annually, and that should be constituted of the minister and two lay delegates from each church, together with three delegates each from the American Unitarian Association, the Western Conference, and such other bodies as might be invited to participate in its deliberations. This Conference was to be only recommendatory in its character, adopting "the existing organizations of the Unitarian body as the instruments of its power." The name of the new organization was the subject of some discussion, James Freeman Clarke wishing to make the Conference one of Independent and Unitarian churches, while another delegate desired to substitute "free Christian" for Unitarian. The desire strongly manifested by a considerable number to make the Conference include in its membership all liberal churches of whatever name not acceptable to the majority of the delegates, voted with a decided emphasis to organize strictly on the Unitarian basis.