Volume 2 (1948-1968) first appeared in 1970. It covers the history of the World Council of Churches from its first assembly at Amsterdam to its fourth assembly at Uppsala, Sweden; analyzes the development of regional ecumenical organizations; and recounts the impact of the Second Vatican Council on the ecumenical witness of the Roman Catholic Church.

Included in this collection of documents from the twentieth-century ecumenical movement are passages from texts produced by assemblies, conferences, and studies of the World Council of Churches and similar bodies, covering three areas of historical concern within modern ecumenism: faith and order, life and work, and mission and evangelism.

This first volume of the series, taking the Reformation as its starting point, covers four centuries of varied endeavours towards church unity in Europe and North America. In particular it deals with the Faith and Order, World Mission and Evangelism, and Life and Work movements in the 20th century, which led to the formation of the World Council of Churches.