Floyd Mayweather vs Manny Pacquiao will be the biggest fight of all time financially and the most significant this century . Evaluating the greatest ever fights is a complex variable of several factors including not only the quality and excitement of the action but the political , social and cultural undertones , the scale of expectation and outside influences . Where Money Man vs PacMan comes to rank among the most important fights in ring history will depend upon what happens that coming night in the MGM Grand Garden Arena . Here is the second of my 12 most significant fights in boxing ’ s history . THE FIGHT AGAINST THE NAZIS . Yankee Stadium , New York . June 22 , 1938 . Joe Louis vs Max Schmeling . Joe Louis ( left ) knocks out Max Schmeling in the first round to win the heavyweight title on June 22 , 1938 . Although Herr Hitler was trumpeting Max Schmeling as a hero of the Third Reich following his knock-out victory over Joe Louis two years earlier , the German was anti-Nazi and remained so during World War II which was imminent at the time of the re-match . Louis had come back from that shock to win the world heavyweight title by defeating James J Braddock but announced he would not consider himself the true champion until he avenged the loss to Schmeling . The fight was billed as a political war between an America struggling to emerge from the Great Depression and a Germany provoking armed conflict in Europe by annexing Austria . Yet such was Schmeling ’ s distaste for being exploited by Adolf Hitler ’ s propaganda machine – and his loyal refusal to sack his Jewish manager – that his wife and mother were refused permission to travel to New York to support him in case he defected to the U.S . The social picture was clouded further by black America ’ s belief in Louis as a high-profile campaigner for Civil Rights . Louis is carried by his supporters ahead of his 1938 re-match with Schmeling . A poster for the rematch ( left ) while Louis and Schmeling shake hands at the weigh-in ahead of their fight . Jack Johnson vs James Jeffries . Louis , who had complacently trained on the links rather in the gym for the first fight , gave up golf and women in serious preparation for the return bout . President Franklin D Roosevelt invited Louis to the White House and told him : 'Joe , we need muscles like yours to beat the Germans. ’ Louis would say : ‘ The whole damned country was depending on me. ’ Clark Gable , Gary Cooper and Gregory Peck were among Hollywood celebrities in the 70,000 crowd , along with FBI boss J Edgar Hoover . Louis is pictured jumping aside as Schmeling falls after the knock-out . Louis had been tactically out-thought in their first fight so decided to go for broke from the first bell . A barrage of left hooks followed by a right to the body had Schmeling doubled-up in pain and referee Arthur Donovan gave him a standing eight count . Louis switched his attack to the head , dropping Schmeling twice , and Donovan called a halt only two minutes and 40 seconds into the fight . Louis , the Brown Bomber , had fractured Schmeling ’ s spine with his body attacks . As the man from Brandenburg was taken to hospital the ambulance passed through Harlem and he recalled later : ‘ I could the noise of crowds dancing . Bands had left the bars and were playing on the sidewalks . Everywhere was filled with celebrations and saxophones. ’ Louis goes on the attack against Schmeling as he gains revenge after defeat two years earlier . Schmeling would be forcibly conscripted as a German paratrooper war but served only briefly and his resistance to Hitler made him a hero in his country for a second time , after the war . He invested in successful businesses and lived until shortly before his 100th birthday , in 2005 . Louis lost his money and became a greeter at Caesars Palace in Las Vegas . His old friend Schmeling visited him there once every year until his death in 1981 , when he acted as a pall-bearer at Louis ’ funeral .
Joe Louis ' and Manny Pacquiao 's fight will be the richest ever . Sportsmail 's Jeff Powell is counting down the ring 's most significant fights . Floyd Mayweather Jr 1938 re-match with Max Schmeling is the second in the series .