Controversial clemency: Notable presidential pardons and shortened sentences

U.S. President Barack Obama's decision to shorten the sentence of Chelsea Manning, who leaked classified documents,is hardly the first time a presidential granting of clemency or a pardon has drawn criticism or focused attention on a contentious chapter of American history.

Brigham Young

The founder of Salt Lake Cityand an early leader of the Mormon Church was pardonedby James Buchanan in 1858 for his role in a conflict between federal forces and Mormon settlers in the Utah Territory.

Convicted conspirators in Abraham Lincoln'sassassination

In 1869, Andrew Johnson pardonedSamuel Arnold, left, Samuel Mudd and EdmundSpangler,who were sentencedin connection with the assassination of Abraham Lincoln.

Jimmy Hoffa

The president of the Teamsters union was convicted of mail fraud and jury tampering. Richard Nixon pardoned him in 1971. The labour leader disappeared in the summer of 1975, and hisbody has not been found.

Richard Nixon

As the Watergate scandal swirled, Richard Nixon resigned on Aug. 9, 1974. Gerald Ford pardoned Nixon a few weeks later for any federal crimes he might have committed while president.

George Steinbrenner

The flamboyant owner of the New York Yankees was convicted of making illegal contributions to Nixon's 1972 re-election campaign. He was pardoned by Ronald Reagan in 1989.

Caspar Weinberger

George H.W. Bush pardoned Caspar Weinberger in 1992. The defence secretary under Reagan had been indicted on charges of perjury and obstruction of justice in connection with the Iran-Contra affair.

Patty Hearst

The heiress to the Heart publishing empire,who was kidnapped in 1974 by the Symbionese Liberation Army,was convicted of bank robbery two years later. Jimmy Carter commuted her sentence, and Bill Clinton gave her a full pardon in 2001.

Marc Rich

Much controversy surrounded Clinton's 2001 pardon of fugitive MarcRich, a financier and international commodities trader indicted on charges of illegal trading with Iran and tax evasion.

Roger Clinton

In 2001, Bill Clinton pardoned his half-brother Roger, who had pleaded guilty to cocaine-related charges seven years earlier.

Lewis (Scooter) Libby

The former chief of staff to Vice-President Dick Cheney was convicted of perjury, obstruction of justice and lying to investigators in a CIA leak case. George W. Bush commuted part ofhis sentence in 2007.