Born in Sparta, Wisconsin, Atwell received an Artium Baccalaureus degree and Bachelor of Science degree from Southwestern University in 1889, and a Bachelor of Laws from the University of Texas School of Law in 1891.

He was the United States Attorney for the Northern District of Texas from 1898 to 1913, thereafter returning to private practice in Dallas until 1924.

[2] Attwell also ran for Governor of Texas in 1922 as a Republican, but lost in a landslide, only receiving 18% of the vote.

[3] Atwell also served as the first commissioner for the Dallas Zoo, a position he held from 1912 to 1914.

He was confirmed by the United States Senate on January 9, 1923, and received his commission the same day.