Question: What kinds of operations did John W. "Jack" Eskridge perform when he joined the United States Marine Corps?
Sentence (from "Jack Eskridge"): Once his professional playing career was over he coached the Atchison High School (Kansas) basketball team to win a state championship before he joined the Kansas Jayhawks men's basketball team as their equipment manager and assistant coach under "Phog" Allen from 1954–59.
Relevant evidence: No