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 are my 12 most significant fights in boxing’s history. THE FIGHT FOR RACE . Jack Johnson v James J Jeffries . July 4, 1910 in Reno, Nevada . Jim Jeffries came out of a six-year retirement to take on Jack Johnson, the first black heavyweight champion . Jack Johnson, as the first black world heavyweight champion, was the bane of the white supremacists in America in the early 1900s. They hated it when the Galveston Giant beat Tommy Burns in Sydney, Australia, in 1908 to win the title they had brandished as the symbol of their racial superiority. Thus began the quest for The Great White Hope. When Johnson KO’d their best hope of all, Stanley Ketchel, the crusade to bring their old idol Jeffries out of six-year retirement reached a frenzy. Jeffries finally agreed ‘to respond to that portion of the white race that has been looking for me to defend its athletic superiority’ – in return for a purse of $120,000 (worth more than three million dollars today). So racist was the press coverage of the build-up to the fight that even The New York Times wrote: ‘If the black man wins, thousands and thousands of his ignorant brothers will misinterpret his victory as justifying claims to much more than mere physical equality with their white neighbours.' As the racial tensions grew, the sheriff of Reno took the then-unusual step of banning guns and alcohol in the 20,000 capacity arena erected down town. Jeffries, by then a contented farmer, had shed more than 100 lbs to get close to his old fighting weight. White America hated it when 'Galveston Giant' Johnson (left) beat Tommy Burns in Sydney, Australia, in 1908 to win the title and after a frenzied campaign, Jeffries (right) agreed to take the fight for what would equal £3m . The bout was scheduled for 45 rounds but Johnson said he knew it was as good as over in the fourth when he saw the alarmed reaction to his trademark uppercut and ‘the old ship sinking.’ Jeffries, hitherto undefeated, had never been off his feet but after two knock-downs his corner threw in the towel at the end of the 15th. He dismayed white America by saying: ‘I could never have whipped Johnson at my best, not in a thousand years.’ Symbolically, the Fourth of July shook the foundations of America’s old white order. Riots broke out that night in 25 cities across the United States and 50 cities including New York and Washington. As police joined enraged white citizens in subduing black American celebrations, 20 people were killed and hundreds injured. Johnson continued to anger the racists on several counts. As heavyweight champion he reigned another five years before surrendering the crown to white challenger Jess Willard, afterwards claiming he had thrown the fight. After beating Jeffries convincingly, Johnson would be world champion for another five years . Johnson then surrendered the crown to white giant Jess Willard, and later claimed to have thrown the fight . Outside the ring he lived the high life of a celebrity and angered the old order again by continuing to marry white wives, three of them in all. The American establishment vented its grudge by accusing him of taking women across state lines for immoral purposes and pursuing him into exile in Europe and Cuba. He finally gave himself up at the Mexican border and served a nominal one-year prison sentence. Before his death, in 1946 at the age of 68, he collaborated on movies about his life and a Broadway play entitled ‘The Great White Hope’ Jack Johnson is still regarded by many boxing historians as the greatest heavyweight of all time.
Floyd Mayweather Jr and Manny Pacquiao's fight will be the richest ever.
Sportmail's Jeff Powell is counting down the ring's most significant fights.
First up is 1910's Fight for Race - Jack Johnson v James J Jeffries.