Milken, who served two years of a 10-year prison sentence and was fined $600 million, went on to co-found the Milken Family Foundation and the Milken Institute while contributing hundreds of millions of dollars to medical research, education and disadvantaged children.
The executive, whose name became synonymous with the go-go Wall Street of the 1980s, "was one of America's greatest financiers," the White House said in a statement after Trump disclosed his pardon of Milken and others, including former Illinois Gov. Rod Blagojevich and former New York police commissioner Bernard Kerik.
Milken's establishment of a market for bonds that were rated below investment grade, or "junk" in industry parlance because of the high risk they wouldn't be repaid, helped small firms get credit that they couldn't have obtained otherwise, enabling them to expand, the administration said.
His work was viewed less charitably 30 years ago, when his guilty plea brought an end to what was, at the time, the largest criminal prosecution in Wall Street history, the New York Times reported.
The former head of the junk-bond business at Drexel Burnham Lambert, Milken fell under government scrutiny when speculator Ivan Boesky agreed to give authorities evidence about malfeasance on Wall Street after a 1986 guilty plea to insider trading, according to the Times.
The charges to which Milken eventually pleaded guilty in Manhattan included a series of illegal transactions with Boesky as well as deals with Solomon Asset Management and its then 49-year-old founder, David B. Solomon, the outlet reported.
Trump's decision was supported by nearly three dozen people, according to the White House, including casino mogul Sheldon Adelson, a campaign donor; Rudy Giuliani, the president's personal attorney; Secretary of Transportation Elaine Chao, the wife of Senate Majority Leader Mitch McConnell; Richard LeFrak, a Queens developer; and Nelson Peltz, the head of private equity firm Trian Partners.
The administration described the charges against Milken as "truly novel," citing a prosecutor who said some of the technical offenses and regulatory violations hadn't previously been the basis of criminal charges. While Milken originally promised to fight them, he pleaded guilty in April 1990 after prosecutors agreed to drop charges against his brother, Lowell.
Milken and his wife of 51 years, Lori, "are very grateful to the president," the former bond executive said in a statement. "We look forward to many more years of pursuing our efforts in medical research, education and public health."
His attorneys had been seeking a presidential pardon since Bill Clinton was in office, according to the Wall Street Journal, but encountered strong opposition from law enforcement.