During his teenage years, he fought in the Golden Gloves as a welterweight and graduated from Boys High School in 1938.
He earned Bachelor and Master of Science degrees from New York University in 1942 and 1947 respectively, the latter after serving in the United States Navy during World War II as a boxing instructor as part of a physical training program headed by heavyweight champion Gene Tunney.
After the war he refereed Golden Gloves and college bouts and became varsity boxing coach at the United States Merchant Marine Academy until the sport was phased out at the intercollegiate level.
Mercante was fit and in shape well into his 80s, often doing a variety of exercises on a daily basis like the jump rope.
Refereeing was his avocation and the line the panel looked for was his vocation; that of beer salesman.