Muhammad Ali, born Cassius Marcellus Clay, Jr., on Jan. 17, 1942, in Louisville, Kentucky, showed an affinity for boxing at an early age. Police officer Joe Martin, who also trained boxers, advised Ali at the age of 12 that he should learn how to fight before challenging the thief who stole his bicycle. Martin later taught Ali how to box, and Ali won his first bout that same year.
In 1956, Ali won the light heavyweight class in the Golden Gloves tournament for novices. He was just 14 years old at the time. He won the National Golden Gloves Tournament of Champions three years later, and in 1960, he won a spot on the U.S. Olympic boxing team, competing in Rome. Ali won the gold medal at age 18.
Ali’s career during the 1960s was successful, and he won most of his matches by knockout. He became the world heavyweight champion in 1964 after defeating Sonny Liston.
Ali faced criticism in 1964 after his conversion to Islam. During this time, he changed his name to Cassius X and then later to Muhammad Ali. In 1966, he cited his religious beliefs as an excuse to dodge a draft notice for service in the Vietnam War. The courts found him guilty of refusing induction into the military, and the boxing association suspended him and stripped him of his title for over three years as a result.