Social Gospel movement books, including The Religion of Revolution and books about Leo Tolstoy, William Lloyd Garrison, Samuel Golden Rule Jones, and the religious movements of the Progressive Era.
http://www.boondocksnet.com/editions/social_gospel.html
An explanation of the theological position of the social gospel movement.
http://spider.georgetowncollege.edu/htallant/courses/his338/students/kpotter/theology.htm
Based in Britain and active in the Labour Party, the CSM is in a tradition that stretches back to the early church. "We all share a belief in justice, peace and the wholeness of creation."
http://www.christiansocialist.org.uk