Herbert Carroll Cassill was born in Percival, Iowa on December 24, 1928. His father, a state school administrator, and his artist mother moved around the midwest. After studying art briefly at Purdue University in Indiana he traveled to studiy printmaking with Mauricio Lasansky at the State University of Iowa, getting his BFA in 1948 and his MFA in 1950. He became an instructor at Iowa between 1953 and 1957. In 1952 he met and married fellow student Washington state native Jean Kubota, who had gotten her MA at the University of Wisconsin, Madison. Both received Louis Comfort Tiffany Scholarships while at Iowa.

The Cassills moved to Cleveland, Ohio in 1957, where Herbert taught printmaking at the Cleveland Institute of Art. Throughout the 1950s and 1960s Cassill alternated between figurative and abstract subjects and images, often of large size. He retired from the Institute in 1991. H.C. Cassill had solo exhibitions at the Oakland Museum (1956), Ohio State University (1960), Cleveland Institute of Art (1966), U of Wisconsin, Madison (1967), Vanderbilt University (1968) to name a few. A retrospective memorial exhibition of his work was held in 2008 at the William Busta Gallery, Cleveland, Ohio. His work is included in numerous public and private collections.

Herbert Carroll (H.C.) Cassill died in Cleveland, Cuyahoga, Ohio on January 18, 2007.