During and after his tenure as American Unitarian Association president, Eliot wrote and edited books on Unitarian and Massachusetts history, including two large biographical dictionaries, the "Biographical History of Massachusetts" (1906) and "Heralds of a Liberal Faith" (1910). The latter volume constituted his efforts to catalog Unitarian history and articulate Unitarianism as a discrete American tradition. Eliot also chaired an editorial committee and edited several volumes for the Centennial Edition of the works of Theodore Parker and completed a "A History of Cambridge, Massachusetts, 1630-1913" in 1913.