Mary M. Treadwell, who directed a jobs training, self-help and minority investment program for inner-city youths, and who later went to jail for using the program to defraud the federal government, died July 21 at her home in Baltimore. She was 71.

The death was announced Tuesday on Twitter by D.C. Council member and former mayor Marion Barry (D-Ward 8). He and Ms. Treadwell were married from 1972 until their divorce in 1977. Barry said his ex-wife had breast cancer but did not know if the disease was the cause of her death.

A prominent player on the D.C. community stage for more than 30 years, Ms. Treadwell was twice sentenced to prison, the first time in 1983, when a judge imposed a three-year term following her conviction for conspiring to defraud the federal government in the operation of the Clifton Terrace Apartments in Northwest Washington.

In 1998, she was sentenced to four months in a federal prison following a guilty plea to stealing $10,400 from a Columbia Heights neighborhood group.

In the 1960s, Ms. Treadwell was a civil rights activist in Washington’s inner city and an organizer of community groups seeking improvements in slum housing conditions, lower bus fare and redress for the harsh treatment of African Americans by city police in the poorest and most downtrodden neighborhoods.

Mary Treadwell, ex-wife of Marion Barry and a figure in his rise to political power, died July 21 at 71. (Stephen Northup/The Washington Post)

In 1967, she and Barry helped start Youth Pride Inc., a federally funded operation that became the city’s best-known jobs training program. It began as an inner city alley cleanup operation and involved hundreds of youths. Later, in an effort to encourage minority entrepreneurship, the program was expanded to include the operation of gas stations and management of residential apartments.

Barry, who was beginning his political ascent with service on the Board of Education and then the D.C. Council, left the Pride program. Ms. Treadwell became its director.

As the Pride programs flourished, so did Ms. Treadwell’s lifestyle. She lived for a period at the Watergate apartment complex, drove a Jaguar and vacationed in Jamaica.

A Pride spinoff, P.I. Properties, acquired the Clifton Terrace Apartments, a 285-unit complex, from the Department of Housing and Urban Development. Ms. Treadwell said she would operate Clifton Terrace as a model complex for low-income tenants.

But witnesses at her nine-week trial testified to repeated instances in which thousands of dollars in tenants’ rent payments intended for use at Clifton Terrace were instead siphoned off for the personal use of Ms. Treadwell or for other business ventures.

Barry was no longer connected with Pride during the period of the Clifton Terrace funds diversion and was not implicated in the plot.

Mary Janine Miller was born April 8, 1941, in Lexington, Ky. She grew up in Columbus, Ohio, where her father was a masonry contractor. Before her marriage to Barry, she had married and divorced David Treadwell, whose surname she kept.

After her marriage to Barry, she married Ronald S. Williams, a Pride financial officer. That marriage also ended in divorce. According to a death notice in The Washington Post, Ms. Treadwell’s survivors include her mother, Ollie Phillips, and a sister, Joan Pullian. A woman who answered the telephone at Ms. Treadwell’s home in Baltimore, where she had lived since 2003, declined to give further details.

Feisty and forceful, Ms. Treadwell was said to have had a dominating personality. James E. Clay, an African American and former Department of Housing and Urban Development official, told The Post in 1983 that she “was able to Mau-Mau her way through my predecessors, especially the whites, by coming on strong as a black militant.” Others said Ms. Treadwell so unnerved officials that they were willing to give her almost anything to get her to leave a meeting.

The federal government, which had pumped more than $20 million into job training programs through Pride, stopped its funding after The Washington Post ran a series of articles on Ms. Treadwell and P.I. Properties in 1979. Youth Pride later went out of business.

Following her release from federal prison, Ms. Treadwell worked for the city government as a specialist on female offenders for the D.C. Parole Board. Later, she worked in the mayor’s office of policy during the administration of Sharon Pratt Kelly.

In January 1998, she was sentenced to four months in prison after pleading guilty to concocting an elaborate check-writing scheme to steal $10,400 from a Columbia Heights Advisory Neighborhood Commission that she headed. She said she needed the money to pay overdue bills.

She was depressed and had low self-esteem, she said at the time.

“I thought, when I came back [from prison] I was ready to put Humpty Dumpty back together again,” she said. “Humpty Dumpty is still cracked.”