On 10 June 1925, the date the United Church of Canada was founded, two-thirds of the congregations of the Presbyterian Church of Canada - including every Presbyterian congregation in Halifax - vanished. Even before the United Church came into existence, however, non-uniting Presbyterians were forming a new congregation.

The Blue Banner is a case study of the survival of historic denominationalism grounded in resistance to church union. It traces the origins and near demise of Presbyterianism in Nova Scotia and the development of Saint David's from its beginnings as a new congregation and the only site of Presbyterian witness in metropolitan Halifax. The authors look at various aspects of congregational life - corporate structure and governance, education, worship and music, volunteerism, mission and outreach, and stewardship of the historic site and building that has been home to Saint David's since the beginning.

Once established, Saint David's - heir to no less than four Scottish Presbyterian traditions - represented a new birth of Presbyterianism in Canada. The Blue Banner considers how the story of Saint David's relates to the mainstream of religious historiography and shows what historians can learn from case studies of local churches viewed in historical perspective.