[8] Dill was narrowly defeated for re-election in 1918 by state supreme court justice J. Stanley Webster.

Dill campaigned as a supporter of Progressive reform and pledged to repeal the Esch–Cummins Act and push for the Columbia Basin Project.

[3] In June 1934, Congress amended the Watson-Parker Railway Labor Act so it explicitly included non-operating train personnel and sleeping car companies.

[3] After he left the Senate, Dill sought a divorce from his wife in 1936, the feminist suffragist and author Rosalie Gardiner Jones of New York.

Dill claimed that Jones told his friends that he was "a political coward" for not seeking re-election in 1934, and that she buried dogs and garbage in the backyard.

[21] Dill met home economics educator Mabel Aileen Dickson (1905–1969) in November 1936 in Washington, DC, and they were married in May 1939.

[22] Born in Crystal, North Dakota, she was raised in Canada; Dickson graduated from the University of Alberta in Edmonton[23] and earned a master's degree at Washington State College in Pullman.