Washington - US President Barack Obama on Wednesday commuted the sentences of 214 drug offenders, the single biggest act of presidential clemency in over a century.
The White House said Obama had forgiven a fresh group of prisoners, including 67 who had been serving life sentences.
Most were guilty of non-violent crimes, many involving possession or distribution of crack cocaine.
The actions "represent the most grants in a single day since at least 1900", said Neil Eggleston, the White House counsel to the president.
Obama has now made 562 commutations, "more commutations than the previous nine presidents combined", Eggleston said.
The move is part of Obama's effort to push ahead with criminal justice reform.
The United States currently has among the world's highest incarceration rates and puts a disproportionate number of black and Hispanic Americans behind bars.
One often cited reason are mandatory sentencing laws for the use of crack that are tougher than those for cocaine.