Prior to this, he was a staff member in the office of the legislative counsel of the U.S. Senate from 1934 to 1946 and Administrative Assistant to President Truman from 1947 to 1950.

During the Great Depression Murphy worked his way through college at Duke University and its law school as a night mail clerk at the post office in Durham.

[1] In 1947 Murphy was named an administrative assistant to President Truman and later served as a speech writer and adviser during his 1948 election campaign.

During the Truman years he was among the small group of advisers and friends called the "little cabinet" that the president sat with in late-evening meetings to develop policy and legislative strategy.

[1] In 1961 President John F. Kennedy appointed him Under Secretary of Agriculture where he handled the detail work on crop controls, price supports, farm subsidies and loans.