After leaving the army as a gifted young competitor, he returned to New York to begin a career as a professional flyweight boxer.
 He was fortunate to have the opportunity to spar frequently in his early career with the exceptional flyweight boxer Frankie Genaro, who would later become a more widely recognized World Flyweight Champion.
 Beginning his career, Schwartz lost to Kid Durand in seven rounds, but defeated Vincent Salvatore, Kid Corona, and Indian Russel.
 He lost to Al Felder, Sammy Bienfeld, and Henry Catena.
Impressively, he fought fifty times before suffering his first knockout.
In his peak years between 1926–27, he won 19 of 25 bouts with only two draws.
After leaving the army as a gifted young competitor, he returned to New York to begin a career as a professional flyweight boxer.  He was fortunate to have the opportunity to spar frequently in his early career with the exceptional flyweight boxer Frankie Genaro, who would later become a more widely recognized World Flyweight Champion.  Beginning his career, Schwartz lost to Kid Durand in seven rounds, but defeated Vincent Salvatore, Kid Corona, and Indian Russel.  He lost to Al Felder, Sammy Bienfeld, and Henry Catena. Impressively, he fought fifty times before suffering his first knockout. In his peak years between 1926–27, he won 19 of 25 bouts with only two draws.
Isadore Schwartz