As seen in the following video, Trump announced the pardon in the Oval Office at the White House, and he was flanked by former heavyweight champion Lennox Lewis, current heavyweight champion Deontay Wilder and actor Sylvester Stallone:
In 1913, Johnson was convicted of violating the Mann Act by taking a woman across state lines for "immoral purposes." Johnson later married the woman.
Johnson fled the country after his sentencing, but he eventually returned and served 10 months in prison.
Johnson became the first African American to win the heavyweight championship when he beat Tommy Burns in 1908.
He went on to hold the title for over six years before losing it to Jess Willard in 1915.
Johnson fought regularly until 1932 before returning to the ring for one bout in 1938 and competing in an exhibition fight in 1945.
He finished his career with a 73-13-10 record and is widely considered one of the best pound-for-pound boxers of all time.
The Galveston, Texas, native died at the age of 68 in 1946, and there had been increased support for a pardon in recent years due to the notion that his prison sentence was racially motivated.