[1] During the Spanish-American war, he joined the United States Army's 1st Volunteer Cavalry Regiment, known as the Rough Riders, where he held the rank of sergeant, and was considered by Theodore Roosevelt "one of the best non-commissioned officers we had".

In citing their qualifications for active duty, Roosevelt touted their athletic accomplishments: Hamilton Fish was "the ex-captain of the Columbia crew"; Dudley Dean was "perhaps the best quarterback who ever played on a Harvard elevan"; Bob Wrenn was "the champion tennis player of America."

Other college athletes included Yale high-jumper Edward C. Waller, steeplechase rider Craig Wadsworth, and polo-player Joe Stephens.

[3] The journalist Burr McIntosh, who was present at the battle, saw his body shortly after his death and observed that "there was no sign of pain, only the faint suggestion of the old smile of victory, which I had so often seen".

[4] Fish's death was widely covered in the press: his youth, his famous family, and his pathetic end made him one of the popular heroes of the war.