He was admitted to the bar in 1929 and commenced private practice of law in Scranton, Pennsylvania from 1929 to 1943.

[1][2] Murphy was elected as a Democrat to the 78th and 79th United States Congresses and served from January 3, 1943, until his resignation on July 17, 1946.

[2] Murphy served on the Joint House-Senate Committee to investigate the attack on Pearl Harbor in 1945.

That led to a close friendship with Vice President Alben W. Barkley, who headed the Senate side of the investigation.

[2] Murphy was made a Knight of the Cross of the Equestrian Order of the Holy Sepulcher in an investiture ceremony at St. Patrick's Cathedral on September 10, 1960.