Walker, a graduate of Gonzaga University, (Spokane, Washington) in 1906 and Notre Dame Law School in 1909, practiced law in Montana and acted as the local Democratic chairman in the 1920 presidential election campaign. He moved to New York City in 1925 as vice-president and general counsel of a movie theatre chain; at the same time he practiced independent corporation law.
He supported Franklin D. Roosevelt's campaigns for governor in 1928 and the presidency in 1932. During the 1932 campaign he served as Treasurer of the Democratic National Committee. President Roosevelt appointed him executive secretary of his President's Executive Council in 1933, and he subsequently acted as executive director of the National Emergency Council.
In 1940 he was appointed to succeed Jim Farley as Postmaster General of the United States, in which position he served until 1945. In 1946 he was appointed by President Truman as alternate delegate to the first United Nations General Assembly session in London. He returned to his business interests in New York as director of W.R. Grace & Co. and the Grace National Bank of New York.
From the description of Papers, 1925-1959. (University of Notre Dame). WorldCat record id: 25391851