Answer
Sylvester Stallone, the renowned actor, played a pivotal role in securing a presidential pardon for Jack Johnson, the pioneering African-American heavyweight boxing champion. Stallone's unwavering commitment to Johnson's cause, fueled by his deep admiration for the boxer's legacy, led him to spearhead a tireless campaign that ultimately culminated in Johnson's long-deserved exoneration, righting a historical injustice that had tarnished Johnson's reputation for decades.