Muhammad Ali, born Cassius Marcellus Clay, Jr., January 17, 1942 – June 3, 2016) was "The Greatest" American professional boxer. From early in his career, Ali was known as an inspiring, controversial and polarizing figure both inside and outside the boxing ring.
Born in Louisville, Kentucky, Ali began training when he was 12 years old. By 22, he won the world heavyweight championship. Shortly after that, Clay converted to Islam, changed his name to Muhammad Ali, and installed a message of racial pride for African Americans.