First North America, Then The World
After the United States entered World War I in 1917, Tunney joined the Marines and was stationed in France. While there, he fought in the American Expeditionary Force light heavyweight championship and won. He continued his civilian boxing career on his return from Europe, moving up the ranks to defeat successively more powerful opponents. Finally, in 1922, Tunney defeated Battling Levinsky in twelve rounds to take the title of light heavyweight boxing champion of North America.
Tunney's success was short lived. Only months later, he was forced to defend his title against Harry Greb, a highly aggressive boxer who was known for intimidating his opponents with unusually savage attacks. Greb gave no quarter to Tunney in their match, pounding away at the champion for fifteen rounds, and using a number of tactics that were on the borderline of legality. Tunney put up a heroic defense, managing to stay on his feet with a broken nose Greb gave him by head-butting him, and with his eyes swollen almost shut, until the fight was ended with Greb the winner by decision.
But Tunney made a comeback the following year, 1923, challenging Greb to a rematch. This fight also went a full fifteen rounds before being called in a decision. This time, however, it was Tunney who got the upper hand. He had taken the advice of a boxing tactician, Benny Leonard, who had advised him to keep Greb off balance with as many punches to the body as he could manage. The strategy paid off, and Tunney took back his North American light heavyweight title.
Tunney now had his ultimate goal in sight: the title of heavyweight boxing champion of the world. This title was held by Jack Dempsey, and the two squared off on September 23, 1926. The match was held at Philadelphia's Sesquicentennial Stadium. This site had been chosen because Dempsey had been banned from fighting in New York because he had refused to accept a challenge from African-American boxer Harry Wills.
Tunney had trained hard for his fight against Dempsey, watching films of the champion in action over and over again, probing for weaknesses. He also enlisted the aid of boxers who had fought Dempsey, both opponents and former sparring partners. Brought to Tunney's training camp, these fighters gave Tunney access to a pool of expert knowledge on Dempsey's fighting strengths and weaknesses from which to draw in the formation of his own strategies. He also drew on his own experience gained during his then-seventy-seven professional bouts, only one of which he had lost.
On the day of the fight, the stadium was jammed with more than 120,000 spectators who shelled out a combined two million dollars to see the championship bout. Tunney's meticulous study of his adversary paid off. He came on strong in the first round, rocking Dempsey with a hard right to the face and then keeping him off balance for the remainder of the bout, until the fight was called in Tunney's favor after ten rounds. It was the first time that anyone had won a heavyweight championship in a decision rather than a knockout.