By Jennifer Hansler, CNN

(CNN) -- President Donald Trump said Saturday that he is considering granting a posthumous pardon to boxer Jack Johnson on the advice of actor Sylvester Stallone.

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

Johnson, the first African-American world heavyweight boxing champion, was convicted in 1913 under the Mann Act for taking his white girlfriend across state lines for "immoral" purposes. The Mann Act purported to prevent human trafficking for the purpose of prostitution, but critics have argued it was applied inconsistently to criminalize African Americans and those with dissenting political views.

Johnson was convicted by an all-white jury in less than two hours and was imprisoned for a year. The sentence and imprisonment destroyed the boxing career of the "Galveston Giant." He died in 1946.

In 2016, then-Sen. Harry Reid and Sen. John McCain, along with Reps. Peter King and Gregory Meeks, petitioned the Obama administration to grant a pardon to Johnson. The bipartisan group of lawmakers sent a letter to the White House asking that the pardon be given in honor of the 70th anniversary of the boxer's death.

"While it is unfortunate that this unjust conviction was not corrected during the boxer's lifetime, a posthumous pardon today represents the opportunity to reaffirm Jack Johnson's substantial contributions to our society and right this historical wrong," the letter said.

In March 2017, Sen. Cory Booker joined with McCain, King and Meeks to reintroduce a resolution urging Johnson's pardon.

"Despite this resolution passing both chambers of Congress several times in recent years, no pardon has been issued to date," McCain said in a statement at the time. "I hope President Trump will seize the opportunity before him to right this historical wrong and restore a great athlete's legacy."

The White House did not immediately return CNN's request for further comment on the President's tweet.