Eliot left congregational ministry to serve as Secretary of the American Unitarian Association (AUA) in 1898. At Eliot's urging, his position was re-titled President in 1900, a title which he retained until 1927 and transformed from a presiding to an executive office. Eliot's efforts to consolidate the National Council of Unitarian Churches under the American Unitarian Association established the denomination's modern associational governance. Where the pre-Eliot AUA had been an organization for individual membership, the merger created a structure of congregational membership and governance, an early incarnation of the Unitarian Universalist Association's General Assembly. Eliot also attracted wealth Unitarians to serve on the AUA's board, who presided over a major expansion of the AUA's operations into public advocacy, Sunday School curriculum, and ministerial credentialing.