Historical narrative can often be grafted on to sporting events in retrospect. When one of the world’s most famous black Americans, Joe Louis, bludgeoned Germany’s Max Schmeling to a first-round defeat in 1938, it was symbolic of free-world endurance against the fascism of Schmeling’s Nazi homeland.

In two minutes and four seconds of brutal efficiency, Louis exploded with a barrage of uppercuts, crosses and hooks to put his opponent on the canvas three times. By the time the fight ended in technical knockout, Schmeling had thrown just four punches, two of which had missed, to Louis’s 31. Many spectators had yet to take their seats.

In victory, Louis delivered the geopolitical message President Franklin D Roosevelt had called for when the fighter had visited the White House just a few weeks prior. “Joe, we need muscles like yours to beat Germany,” the New York Times quoted the president as telling the Brown Bomber ahead of the bout.

Hitler had passed the Nuremberg Race Laws a year earlier, the extension of which would soon see black people like Louis, along with Jews and Roma people, categorized as legally inferior to whites within the Reich.

The growing boldness of Nazi policy was drawing international condemnation, but for a black man who grew up the son of an Alabama sharecropper and whose family had been harassed by the KKK, the use of colour to distinguish citizen rights was an all too familiar aspect of life in America.

It was a situation reflected by sentiments that surrounded the first meeting between the two fighters at Yankee Stadium, almost two-years-to-the-day prior to Louis’ famous win.

Related: Joe Louis, the greatest of the heavyweights, dies – archive, 13 April 1981

“When he fought in 1936, a lot of white America rooted for the German,” Joseph Louis Barrow Jr tells the Guardian of his father’s challenge.

Those who did support Schmeling that day in the Bronx went home happy, as the odds-on-favorite Louis was knocked out in the 12th-round for the first defeat of his career.

“He felt he’d let the entire black race down because he was not supposed to lose that fight. He was supposed to win it, and win it with great applause,” Louis Barrow Jr says, speaking from his home in Jacksonville, Florida.

The defeat was all the more significant because it happened on 19 June, a date more recently dubbed Juneteenth to commemorate the day when news of the Emancipation Proclamation reached the people of Galveston, Texas, freeing slaves in the last rebel state.

This year will be the first time Juneteenth is marked as an official federal holiday in America, but 85 years ago the Louis defeat led to a day of mourning for many black Americans.

Langston Hughes, a leading writer of the Harlem Renaissance, wrote of the defeat’s aftermath by saying: “I walked down Seventh Avenue and saw grown men weeping like children, and women sitting in the curbs with their head in their hands. All across the country that night when the news came that Joe was knocked out, people cried. No one else in the United States has ever had such an effect on Negro emotions – or on mine.”

Indeed in Louis’s prime, his actions in the ring reverberated around the world, as Louis Barrow Jr details in his book Joe Louis: 50 Years and American Hero. “You know, Nelson Mandela, when he came over to the United States after he was freed from Robben Island told me that he, along with thousands of black people in South Africa, had stayed awake to listen to my father’s fights on the radio,” he wrote. “It provided them with hope.”

Beneath the veneer of political narrative however, the reasons for sporting loss can often be far more prosaic.

“My father was the invincible Joe [who was 22 at the time] fighting a man eight years older,” says Louis Barrow Jr. “It resulted in him not preparing to fight the way he should have. He was spending more time on the golf course.”

It made Louis’ fight to avenge his loss all the more compelling to fight fans of the era. Such was the thirst for action in the 1930s, Louis fought and beat 11 opponents in the two years he waited to meet Schmeling once again in Yankee Stadium. He took the heavyweight title from Jack Braddock in 1937 proving the perfect lure for a belt-less Schmeling to agree to a rematch.

Over the same time period, Hitler had opened the Buchenwald concentration camp and annexed Austria, ramping up global tensions.

Schmeling was held up by Nazi propagandists as a poster boy of an Aryan race with a sacred destiny, all of which added to the drama of the fight which had sold out the 75,000 tickets soon after being announced. Not that the fighters involved necessarily shared the polarization of the build up.

“To some it was freedom and democracy versus fascism, FDR versus Adolf Hitler. It meant different things to different people but to Max and my father it was really just the meeting of two gladiators,” says Louis Barrow Jr.

Louis was in the shape of his life and carried a ferocious hunger into the ring that night. His win not only avenged the sole loss of this career to that point, it propelled him into the center of American culture and adoration.

“He was on the front page above the fold of every newspaper, without killing a white person,” Louis Barrow Jr says of the coverage. “I think all of America admired him and black America had a special affection. Many young boys were named Louis or Joe, many young girls who were named Marva, after my mother, and that was because of the admiration that they had for my father.”

It was a national admiration that didn’t stop at the naming babies born in the shadow of his win.

“Many of the civil rights icons said they were only able to do what they did, because of my father. Jesse Jackson, said before there was a was a Jackie, meaning Jackie Robinson, there was a Joe,” he says. “I knew John Lewis, the congressman from Atlanta, [and one of the Big Six organizers of the 1963 civil rights march on Washington] and every time I would see him he’d talk about what my father meant to him. How he was a man who proved to America that black people were more than just slaves.”

Luminaries from boxing heaped praise on Louis too.

“Muhammad Ali told me at my father’s funeral that Joe Louis was truly the greatest. And I’m going to believe Ali, because that was my man. I grew up in the Ali era,” Louis Barrow Jr adds.

The World Boxing Council and Gleason’s Gym, founded in New York just a few months before Louis beat Schmeling in the summer of 1938, will celebrate the Louis v Schmeling fight in one of many events taking place across the United States for the anniversary weekend.

A presentation of a special Juneteenth belt will be made to the local Eagle Academy for Young Men of Harlem, by former heavyweight champion Michael Spinks. It will help Spinks to honor the boxer he “took his jab from,” he tells the Guardian via email. For Gleason’s Gym owner Bruce Silverglade, it shows Louis’ ability to inspire the next generation remains potent even after all of these years.

“He may be a boxer from a time gone by, but he crossed cultural divisions during a tough time in the United States,” says Silverglade. “White people promoted him. He transcended the racial barriers because he was a hero. Boxing is a sport that crosses barriers, the kids in my gyms are all shapes and sizes and colors, from all different backgrounds. All humans trying to do the same thing, and figures like Joe Louis bring people together.”

For all the emphasis on the racial and politics differences that the fight was supposed to symbolise, it forged only a lasting friendship between the two protagonists.

“I have pictures of Max and my father,” Louis Barrow Jr says. “From trips when he went to Germany to cover fights too. Max appeared on my father’s This Is Your Life, I was only four or five then. Their friendship was wonderful. In fact, when my father died, Max said he lost a great friend. You could see the smile on Max’s face when I talked with him about my father for my book, and we spoke about the ’36 fight at length. The ’38 fight, not so much!”

When asked how he feels watching the Schmeling fights back again, after all these years, Louis Barrow Jr is clear.

“One word that comes to mind: pride. He held the heavyweight title with dignity and grace for almost 12 years, but the Schmeling fight turned him from a heavyweight champion to a true American hero, because all America rooted for him.”