Joe Gans
Joe Gans is often credited with being the greatest lightweight fighter of all time. He is notable for being the first African-American world champion in the sport.
Gans held the lightweight title for a stretch of six years, between 1902 and 1908, and helped blaze the path for African-American fighters. His official record stands at 145-10-16 and that is a big deal considering the fact that he was active for only 16 years.