Complex sentence: He eventually became president of that union, and then served as Director of Labor for the State of Illinois from 1933 to 1941, during which time, and worked closely with the President Franklin D. Roosevelt's Secretary of Labor, Frances Perkins.
Split into simpler sentences: He eventually became president of that union, and then served as Director of Labor for the State of Illinois from 1933 to 1941. He worked closely with the President Franklin D. Roosevelt's Secretary of Labor, Frances Perkins.