Conversation so far:
What was Bob Feller doing in his later life?
Feller was elected the inaugural president of the Major League Baseball Players' Association in 1956.
What did Bob Feller do as president of the association?
As president, he appeared before Congress to speak about baseball's reserve clause.

Question: What other things was he doing?
Self-contained rewrite: What other things was Bob Feller doing besides serving as president of the MLB players association?