Cassidy was also the head basketball coach at Colorado Agricultural for the 1910–11 season, tallying a mark of 5–4.

[1] Cassidy attended the University of Vermont, where he participiated in football, basketball and baseball and track.

[2][3] From 1911 to 1913, he coach and served as athletic director at Saint Anselm College in Goffstown, New Hampshire.

He left the United States in 1913 to coach and direct athletics at the University of the Philippines in Manila.

There he mentored Abraham Ribicoff, who was later the government of Connecticut and United States Secretary of Health, Education, and Welfare.