After winning his first 19 fights, including 15 knockouts, Clay received his first title shot on February 25, 1964, against reigning heavyweight champion Sonny Liston (1932-1970). Although he arrived in Miami Beach, Florida, a 7-1 underdog, the 22-year-old Clay relentlessly taunted Liston before the fight, promising to “float like a butterfly, sting like a bee” and predicting a knockout. When Liston failed to answer the bell at the start of the seventh round, Clay was indeed crowned heavyweight champion of the world. In the ring after the fight, the new champ roared, “I am the greatest!”
At a press conference the next morning, Clay, who had been seen around Miami with controversial Nation of Islam member Malcolm X (1925-1965), confirmed the rumors of his conversion to Islam. On March 6, 1964, Nation of Islam leader Elijah Muhammad (1897-1975) bestowed on Clay the name of Muhammad Ali.
Ali solidified his hold on the heavyweight championship by knocking out Liston in the first round of their rematch on May 25, 1965, and he defended his title eight more times. Then, with the Vietnam War raging, Ali showed up for his scheduled induction into the U.S. Armed Forces on April 28, 1967. Citing his religious beliefs, he refused to serve. Ali was arrested, and the New York State Athletic Commission immediately suspended his boxing license and revoked his heavyweight belt.
Convicted of draft evasion, Ali was sentenced to the maximum of five years in prison and a $10,000 fine, but he remained free while the conviction was appealed. Many saw Ali as a draft dodger, and his popularity plummeted. Banned from boxing for three years, Ali spoke out against the Vietnam War on college campuses. As public attitudes turned against the war, support for Ali grew. In 1970 the New York State Supreme Court ordered his boxing license reinstated, and the following year the U.S. Supreme Court overturned his conviction in a unanimous decision.