President Donald Trump has granted a rare posthumous pardon to boxing's first black heavyweight champion more than 100 years after what Trump said many feel was a racially motivated injustice.

Jack Johnson was convicted in 1913 by an all-white jury for violating the Mann Act, which made it illegal to transport women across state lines for "immoral" purposes.

Trump was joined by boxer Lennox Lewis and actor Sylvester Stallone as he announced the decision.

Stallone, who starred in the "Rocky" series," had urged Trump to grant the pardon.

"I believe that Jack Johnson is a very worthy person to receive a full pardon, and in this case, a posthumous pardon," the president said, with Jackson's family members and Stallone surrounding him. "So I am taking this very righteous step, I believe, to correct a wrong that occurred in our history and to honor a truly legendary boxing champion."

Johnson, who died in 1946, was convicted by an all-white jury in Chicago in 1913 of violating the Jim Crow-era White-Slave Traffic Act, that was intended to prevent and punish human trafficking and was used on Johnson for traveling with a white woman. The conviction was carried out even though the alleged crime took place before the law had passed. Johnson skipped bail and fled the country, living in exile, before ultimately surrendering and returning to service his one-year sentence.

"We have done something today that was very important, because we righted a wrong," Trump said. "Jack Johnson was not treated fairly, and we have corrected that, and I'm very honored to have done it."

Johnson is a legendary figure in boxing, who crossed over into popular culture decades ago with biographies, dramas and documentaries following the civil rights era.

Sen. John McCain and former Senate Majority Leader Harry Reid had also pushed Johnson's case for years.

Johnson fought Jim Jeffries in Reno on July 4, 1910 in what was dubbed the 'Fight of the Century.' He won that fight in front of a crowd of 20,000 people. A state historical marker now commemorates the fight, which was located near East 4th and Toano Streets.

(The Associated Press, CBS News contributed to this report.)