When did the man dubbed  "the most influential private citizen in the America of his day" hire Elmo Roper?
Elmo Roper:  He was hired by Henry Luce in 1935 to run surveys for "Fortune", continuing these surveys for 15 years. Henry Luce: Henry Robinson Luce (April 3, 1898 – February 28, 1967) was an American magazine magnate who was called "the most influential private citizen in the America of his day".
1935