Steward was born in West Virginia, and by the age of 12, he had moved with his mother to Detroit, Michigan. Before that, Steward had boxed on some play bouts his father had set up with his neighbor friends. When he moved to Detroit, he immediately submerged into the Brewster Recreation Center, where fellow hall of famers Joe Louis and Eddie Futch had trained before. Steward was able to compile a record of 95 wins and 3 losses as an amateur boxer, and he won many tournaments, including the 1963 national Golden Gloves tournament. He soon started training amateur boxers,but because of his family's economical situation, he needed a steady job, and so he became an electrician.
Soon after, he was asked to look out for his half brother James. This was 1971, and Emanuel took James to the nearby Kronk Gym. Emanuel got interested in coaching boxers again while he attended Kronk with James.
By the 1970s, Kronk had become an amateur boxer hot-bed, as many of the United States top amateur contenders came to be trained by Steward, and eventually, many of these guys went to the professional rankings and became world champions. By the late '70s, Steward had become known in the boxing world as a trainer.
During the 1980s, those amateur guys that came to Kronk to work under Steward had begun to become world champions,(On March 2 of 1980 Hilmer Kenty became Steward's first world champion by knocking out world Lightweight champ Ernesto Espana), and Steward often found himself involved in some of boxing's biggest events as a trainer, such as The War, where Steward trainee Thomas Hearns faced Marvin Hagler for the world Middleweight title, and Hearns' fights with Wilfredo Benitez, Roberto Duran and Sugar Ray Leonard.
Kronk became a property of Steward, who now is famous also for his collection of Rolls Royce cars and mansion. He opened a branch of the gym in Tucson, Arizona, and has started an association with the Dodge Theater in Phoenix to present boxing undercards once a month. Teenage amateur prospect Ernie Gonzalez has been boxing in some of those undercards, which brings an interesting twist to Steward's cards, because usually boxing cards do not include both amateur and professional fights the same night.
Among the world champions who have trained or seeked Steward's guidance at some point of their career are: