Twice decorated as a Medal of Honor winner, John McCloy served in what was called the American Relief Expedition to China, in Vera Cruz, Mexico, and in World War I. For his first medal awarded in 1901, he was recognized for his "distinguished conduct in the presence of the enemy in battles" during June of the previous year. Awarded a second medal in 1915, McCloy led three launches in a successful attempt to rescue men trapped on the shores of Vera Cruz, Mexico. He sustained an injury, but did not abandon his post.
In World War I, McCloy cleared out sea mines in the U.S.S. Curlew, a ship equipped as a minesweeper. For these actions, he received the Navy Cross.