Conversation so far:
What was the Chautauqua circuit?
Bryan was the most popular speaker on the Chautauqua circuit, delivering thousands of paid speeches on current events.
What are some examples of the topics that he spoke about?
He mostly spoke about Christianity, but covered a wide variety of topics.
What was his topic on Christianity about?
stressed that Christian theology was the solid foundation of morality.
What is another topic that he spoke on?
In a 1905 speech, Bryan warned that "the Darwinian theory represents man reaching his present perfection by the operation of the law of hate.
Did he do any other work besides speeches during this period?
Bryan threw himself into the work of the Social Gospel.
He served in organizations.

Question: What organizations did he serve in?
Self-contained rewrite: What organizations did William Jennings Bryan serve in?