John Dodick was born on December 5, 1899, in New York's Lower East Side, the second of seven children. He was compelled to drop out of elementary school to help his father, a fruitseller, support their large family. K. O. Brown, a leading lightweight contender, was reputed to be his first mentor at the Boys Club he attended, and a source of encouragement. According to one source, Dodick's third bout was with future lightweight legend Benny Leonard in a no decision six rounder. Dodick debuted in the New York fight clubs under the name "Young Kiddy" at age 15.