It has been nearly fifty years since the Rev. Eugene Carson Blake, Stated Clerk of the United Presbyterian Church in the USA, proposed in a sermon at Grace Episcopal Cathedral, San Francisco, the establishment of a dialogue between the Protestant Episcopal Church and the United Presbyterian Church in the USA, in the hope that this would result in a united church that would be “truly catholic, truly reformed, and truly
evangelical”. This would later be expanded to include the United Methodist Church and, subsequently, seven other denominations, including three historically black Methodist denominations. This would give rise to the Consultation on Church Union, which would subsequently be succeeded in this vision in 2001 by Churches Uniting in Christ, with ten denominations from the Reformed, Anglican, Methodist and Moravian traditions.
Historically, Anglicanism and Presbyterianism grew up as cousins, if not siblings, in England, Scotland and later in Ireland and Wales, and these traditions were transplanted into the American context during the colonial period. Having had common roots in Britain, as well as in the colonies, and being generally of similar socio-economic and educational levels, Presbyterians and Episcopalians have over the years engaged in conversations towards unity on and off since the 1890s.
The definitive statement of the basis for church union in the Episcopal Church, indeed in Anglicanism as a whole, is the Chicago-Lambeth Quadrilateral. Originally an invitation by the American Episcopal Bishops to discussions of union with various other church bodies, churches from the Presbyterian tradition alone responded. There were no permanent results of these discussions, although these conversations were background to subsequent and serious proposals towards meger in the 1940s.