Before his fall from grace, Barry had been one of the nation's most promising black politicians. Years later, many Washingtonians would consider him a scoundrel but he remained a hero to many others in impoverished parts of the city, even as his continuing battles with substance abuse went public.
Barry, who was serving as a city councilman, was hospitalized briefly last week and collapsed hours after being released on Saturday night, media reports said. He died at the United Medical Center in Washington, spokeswoman Natalie Williams said. The cause of death was not disclosed.
Barry served three terms from 1979 until 1991 when he went to prison for six months. He reclaimed the job in 1995.
Gregarious and charismatic, he came to be known as Washington's "mayor for life", a label he said he disliked but still used in the title of his autobiography "Mayor for Life: The Incredible Story of Marion Barry, Jr."
President Barack Obama noted Barry's sometimes "tumultuous" life and career but said he advanced civil rights for all.
"During his decades in elected office in D.C., he put in place historic programs to lift working people out of poverty, expand opportunity, and begin to make real the promise of home rule," Obama said in a statement on Sunday.
Barry's third term was sullied by open talk of womanizing, drinking and drug use, making him an easy target for comedians and drawing media disdain. Several top aides were convicted of corruption. Barry responded to criticism with denials and claims that he was the victim of a racist media.
In his autobiography Barry said he was fueled in those days by a "mix of power, attraction, alcohol, sex and drugs".
On Jan. 18, 1990, the married Barry met an ex-girlfriend, former model Rasheeda Moore, in Washington's Vista Hotel. Hidden cameras captured him asking Moore about the possibility of having sex and then smoking a crack pipe before FBI agents and police rushed in to arrest him.
During his six-week trial, in the midst of a Washington crack epidemic and a rash of drug-related homicides, Moore testified that she and Barry had used cocaine as many as 100 times.
Barry's lawyers pursued an entrapment defense and claimed victory when the jury convicted him on only a misdemeanor count of cocaine possession. Jurors acquitted him of another possession charge and were deadlocked on 12 other charges.
JAIL TERM
In sentencing Barry to six months in prison, the judge said the mayor had "given aid, comfort and encouragement to the drug culture at large and contributed to the anguish that illegal drugs have inflicted on this city in so many ways for so long".
Prison could have meant the end of politics for the son of a sharecropper from Itta Bena, Mississippi. But the humiliation did not kill his political career.
Upon his release, Barry moved to Washington's Ward 8, one of the city's grittiest areas, and easily won a City Council seat in 1992. His campaign slogan was "I may not be perfect but I am perfect for Washington".
Two years later he shocked the nation by reclaiming the mayor's job with 56 percent of the vote, though this time with very little support from white voters.
Barry did not seek re-election at the end of his four-year term and went into consulting work. But he could not stay away politics and in 2004 easily won a seat on the City Council.
Barry started out in the civil rights movement while a student at Le Moyne College and Fisk University in Tennessee, and took a leadership role before being sent to Washington to continue his work.
He organized a boycott to protest against rising city bus fares and campaigned for home rule for the District of Columbia, which was controlled by the federal government.
Barry's first elected job was on the Washington school board, becoming a national figure over the next 10 years. As a city councilman in 1977 he was shot by a group of Hanafi Muslims during a hostage crisis at the city's government building.
He became mayor in 1979 with broad support from both black and white voters, focusing resources on poor neighborhoods, government contracts for black businesses and the creation of jobs on the city payroll.
Barry was married four times and had one son.
