It was Sylvester Stallone who got President Donald Trump thinking about legendary boxer Jack Johnson.

Trump tweeted Saturday that he's considering pardoning Johnson, boxing's first black heavyweight champion, more than 100 years after he was convicted by all-white jury of accompanying a white woman across state lines, the Associated Press reported.

Sylvester Stallone called me with the story of heavyweight boxing champion Jack Johnson. His trials and tribulations were great, his life complex and controversial. Others have looked at this over the years, most thought it would be done, but yes, I am considering a Full Pardon! — Donald J. Trump (@realDonaldTrump) April 21, 2018

Johnson, a Galveston native, was convicted in 1913 for violating the Mann Act, which made it illegal to transport women across state lines for "immoral" purposes -- which at the time included interracial relationships. He died in 1946 in a car crash.

Johnson defeated Tommy Burns for the heavyweight title in 1908 when blacks and whites rarely fought each other in the ring. He became one of the country's most despised citizens in the eyes of whites as he defeated a series of "great white hopes," including a devastating domination of former champion James Jeffries in 1910.

"I could never have whipped Johnson at my best," Jeffries said after the fight. "I couldn't have hit him. No, I couldn't have reached him in 1,000 years."

Johnson also lived lavishly and dated outside of his race in a time when whites often killed blacks without fear of legal repercussions.

Stallone, who starred in the 1976 boxing film Rocky and its sequels, is a supporter of the president and attended Trump's New Years' Eve party at Mar-a-Lago in 2016, the AP reported.

A movement to pardon Johnson posthumously has been building for years.

Linda E. Haywood, the great-niece of boxing legend Jack Johnson, gets a close-up look at Adrienne Isom's life-size statue of the boxer during the dedication of the John Arthur "Jack" Johnson Park in Galveston in 2012. (Jennifer Reynolds / AP)

"I know he's passed away, but this is more about the need for an apology," playwright Tommie J. Moore said in the New York Daily News.

Several politicians, including Republican Sen. John McCain and Democratic Sen. Harry Reid have also pushed for Johnson's record to be wiped clean.

"Johnson's imprisonment forced him into the shadows of bigotry and prejudice, and continues to stand as a stain on our national honor," McCain said, according to AP.

A bill that was passed by the House of Representatives in 2008 failed in the Senate, but other proposals have been approved, most recently in 2015.

Recently, Trump pardoned Scooter Libby, former chief of staff to former Vice President Dick Cheney, who was convicted of lying to the FBI in leaking the identity of covert CIA agent Valerie Plame.

Last year, he pardoned controversial former Arizona sheriff Joe Arpaio, after he had been convicted of racially profiling Hispanics.

The Associated Press, The Washington Post, The Hill and Biography.com contributed to this report.