He received an Artium Baccalaureus degree from Georgetown University in 1881, and read law to enter the bar in 1883.

He was confirmed by the United States Senate on May 18, 1909, and received his commission the same day.

[1] Donworth returned to private practice in Seattle from 1912 to 1918, when he entered the United States Army, serving until 1922.

He thereafter remained in private practice in Seattle from 1922 until his death in that city on September 6, 1947.

[1] His son, Charles T. Donworth, later became a justice of the Washington Supreme Court.