Conversation so far:
What was the AFL?
The American Federation of Labor (AFL) was a national federation of labor unions in the United States founded in Columbus, Ohio.
What was the CIO?
The Congress of Industrial Organizations (CIO) was a federation of unions that organized workers in industrial unions in the United States and Canada from 1935 to 1955.
When did the AFL and the CIO merge?
On December 1955 a joint convention in New York City merged the two federations, creating the AFL-CIO.

Question: What leadership position did he hold with the AFL?
Self-contained rewrite: What leadership position did he hold with the AFL?