Background
He was born in Worcester, Massachusetts as the son of William John D'Ewart and Mary Elizabeth Barnard.
United States representative politician Member of the Montana House of Representatives member of the State Senate of Montana
He was born in Worcester, Massachusetts as the son of William John D'Ewart and Mary Elizabeth Barnard.
He attended Washington State College at Pullman and moved to Montana, where he settled in Park County, working as a businessman.
From 1937 to 1939, he served in the Montana House of Representatives, and from 1941 to 1945, he served in the Montana Senate. D'Ewart was re-elected in 1950 and 1952 against John J. Holmes. Rather than seek re-election, D'Ewart ran for the United States Senate against incumbent Democratic Senator James E. Murray in 1954.
D'Ewart served as an assistant to the United States Secretary of Agriculture from January 1955 to September 1955. He was Assistant Secretary of the Department of the Interior from October 1955 to July 1956. From August 1956 to October 1958 he was a special representative for the Secretary of Agriculture.
When incumbent Governor J. Hugo Aronson declined to seek reelection as Governor of Montana in 1960, D'Ewart ran to succeed him, and lost to former State Senator Donald Grant Nutter in the Republican primary by fewer than five hundred votes. D'Ewart was a director of the National Water Resources Association, and he served on the Western States Water Council from 1966 to 1969. He died in Livingston, Montana, on September 2, 1973.
D'Ewart was buried at Mountain View Cemetery in Livingston.