Boxing legend Joe Louis successfully defended his heavyweight title for the 20th time on this day in 1942 – then hours later joined the U.S. Army.
The 27-year-old, who was dubbed “white America's first black hero”, donated all of his $47,000 proceeds from his fight with Buddy Baer to the U.S. Navy. His charity, however, was not matched by mercy for his opponent - and 18,870 fans at New York's Madison Square Gardens saw Louis pulverise Baer.
He knocked his compatriot out in the first round after twice sending him onto the canvas with his trademark powerful blows.
The aggression echoed his 1936 fight with German Max Schmeling, which had pitted Nazi notions of white supremacy against U.S. democracy and made Louis a hero.
The following day Louis – mindful of the fact that America had been at war for a month following the Japanese attack on Pearl Harbor – enlisted in the army.
A British Pathé newsreel filmed the boxer – real name Joe Louis Barrow - being asked routine questions as he registered at Camp Upton on Long Island, New York.
When the soldier-clerk asked his occupation, Louis nervously replied: “Fighting and let us at them Japs.”
He was later shown undergoing a physical examination and – in spite of receiving a few blows and a cut lip the night before – was judged to be in perfect shape.
The son of desperately poor Alabama sharecroppers finally saluted the American flag and began his stint as a private, which largely served propaganda purposes.
He fought almost 100 exhibitions in front of two million servicemen and toured the world with other stars, including fellow boxer Sugar Ray Robinson.
Louis also appeared on a poster campaign with the slogan: “We’ll win because we’re on God’s side.”
And, despite opposing racial segregation, he agreed to join an all-black unit after saying: “Lots of things wrong with America, but Hitler ain't going to fix them.”
He used his influence to help African Americans, including Jackie Robinson, who became the first black play Major League Baseball, be considered for officer training.
After the war, Louis defended his title three more times before retiring in 1948.
But he was forced into a humiliating return in 1952 after tax collectors – ignoring his charity and service during the war – demanded a back payment of $1.2million.
He had already spent the remainder of the $5million he earned during his career on extravagances and generosity.
Later in his life he helped end the Professional Golf Association of America’s white-only rule following the public outcry when he was barred from a tournament.
But in spite of his efforts to end segregation, Muhammad Ali, who came to dominate boxing in the 1960s, accused him of being an “Uncle Tom”.
He used the slur – meaning a black man who is excessively subservient to whites – after Louis criticised Ali for refusing to serve in Vietnam.
Among the black Muslim convert’s criticism was that Louis adhered to managers’ guidance of not posing for photographs with white girls.
Yet, for most Americans, Louis represents a sporting role model that few have ever matched since.