[1] As the United States moved towards participation in World War I, he was commissioned as a first lieutenant in the U. S. Army's Aviation Section, U.S. Signal Corps, and in 1917, was put in charge of Loyal Legion of Loggers and Lumbermen, the company union for the Army's Spruce Production Division which supplied lumber for military aircraft and ships.

[1] In 1921, Crumpacker was appointed special deputy district attorney for Multnomah County, and ran unsuccessfully for the Republican nomination for U.S. Congress in 1922.

[1] In July 1927, Crumpacker was invited by House speaker Nicholas Longworth to journey down the west coast from Seattle in a special train car as the guest of a Northern Pacific Railroad director.

The train arrived in San Francisco on July 22, with plans to travel on to Salinas and then to California Senator James D. Phelan's ranch the next day.

[6] He was eventually subdued, handcuffed, and taken to the hospital, where the evaluating physician noted that he appeared to be "under a great nervous strain" and showing "symptoms of a paranoiac.