Born in New York, Chalmers was one of the most successful athletes in Lafayette College history. He graduated in 1902. In 1901, his coaching career began at Dubuque High School in Dubuque, Iowa. He led the D.H.S. football team to the state title in the championship game against West Des Monies High School; the final score read 12–0 in favor of D.H.S. Chalmers then served as athletic director at Franklin & Marshall College for a year before being hired to replace Alden Knipe as head football coach at the University of Iowa in 1903.