Question: When did the man dubbed  "the most influential private citizen in the America of his day" hire Elmo Roper?
Sentence (from "Henry Luce"): "Time" summarized and interpreted the week's news; "Life" was a picture magazine of politics, culture, and society that dominated American visual perceptions in the era before television; "Fortune" explored in depth the economy and the world business; and "Sports Illustrated" explored the motivations and strategies of sports teams and key players.
Relevant evidence: No