Jack Johnson was the greatest Heavyweight of all time.
He beat 3 of the guys in my top 20, 1 of which is in my top 10. He also beat 2 different guys in the average random old racist white guy's top 10 list (Corbett and Jeffries).
This man could have been Heavyweight Champion for 20 years, but here's why it was only 7:
You see, the man by the name of James J. Jeffries was Heavyweight Champion from 1899 to when he relinquished it around 1905 and retired. He beat the ALL time great lb for lb fighter in Bob Fitzsimmons to win the title, (Fitz is the only man to this day to have been undisputed Middleweight, Light Heavyweight, and Heavyweight Champion). Took over 100 years later till Jones became at least a partial champion in all these weight divisions. James Toney is dead set on being the third man to do it and already has except they took his title away after beating Ruiz for some bullshit drug charge, ruling the bout a NC. Anyways, Jeffries outweighed Fitz by 40 lbs that night. Jeffries lead an undefeated career until he retired, defending his title against the best White Heavyweights that were around including the father of technical boxing himself in Jim Corbett. That was the thing tho, only White Heavyweights. He publicly refused to fight Black fighters, even if their name was Jack Johnson.
By 1903 Johnson had become the World Colored Heavyweight champion and soon began to call out Jeffries to fight him. While the White world refused to acknowledge Johnson, he goes on to defend his 'Colored' title against some of the greatest Heavyweights of all time. His very first title defense is against Sam McVea in the first of 3 victories against him. McVea never beats Johnson. He later defends it against Joe Jeannette several times and Sam Langford once. God only knows how many times he had fights with Joe Jeannette. If anyone had his number, it was him. A lot of the fights there isn't even an official decision on, but towards the end of the string of 10 or so fights Johnson was recorded to have consecutive wins. Johnson only lost once in all those fights, and it was by DQ. Johnson was also beating all the best White competition around in non-title bouts. Johnson never lost his Colored Heavyweight championship but relinquished it when he finally got a title shot at the end of 1908 from Tommy Burns.
Johnson demolishes nearly every White man America throws at him. White people became so desperate they pull the great James Jeffries out of retirement to fight him. Jeffries was now however another 6 years older and a good 100 lbs overweight. Johnson toys with Jeffries, carrying him 15 rounds before he takes him out. Johnson was rarely in a safe place while fighting Whites, police had to prevent fans from killing him they were so upset. Johnson remained champion until 1915 in a questionable performance against Jess Willard where he appears to take a dive during the 26th round. Considering what happens next, I believe he was given the option to lose the fight in a convincing fashion, or be killed. Boxing had finally had enough of Johnson's flamboyance and larger than life character, awarding him no rematch. He was then wrongfully convicted of violating the Mann Act and fled to country to avoid prison. Johnson continued to fight overseas never losing for the next 5 years. He made his returning debut in the US fighting in prison (surrendering himself over to authorities). After he got out he continued to fight, but was never allowed on the main stage again. He didn't lose again until 1926 at the age of 48, remaining undefeated for the 11 years since his exile. By 1919 Jack Dempsey had become Heavyweight Champion and adopted the same principles Jeffries had. The Boxing world would have to wait until 1937 until the next Black man got a shot at the title. His name was Joe Louis, and he was the second greatest of all time.
The top guys I was referring to earlier:
1) Sam Langford: A top 10 all time Heavyweight, and the only 1 to never win the World Championship.
2) Joe Jeannette: A top 20 all time Heavyweight, former World Colored Heavyweight champion. Had battles with all the greatest Black fighters of the time, but could never beat the younger more talented Harry Wills (a top 10 Heavyweight of all time).
3) Sam McVea: A top 20 all time Heavyweight, usually lost or drew with Langford, but would win occasionally. Usually lost to Harry Wills but beat him once too.