The Southern Illinois Christian Conference was organized in 1833. They held a meeting at Union Hill Christian Church October 24, 1896 for the purpose of incorporating. They also held a special meeting at Mount Carbon Christian church December 19, 1936 for the purpose of becoming a religious corporation. This incorporation was filed March 18th, 1937.
In 1927, E.M. Williams compiled and wrote about how the conference started in Biblical Dialogues in the Christian Record (PDF Document). It is in this writing that E.M. Williams references What of the Christians? A statement of the Principles and Characteristics of the Christians (PDF Document) written by Rev. J. Alex Clapp in 1891.