As a youth, he ran with a street gang, but made a turn-around in 1968 and devoted himself to reviving the Young Lords to work on issues of human rights, beginning in Chicago.

Issues included redlining, displacement of the poor, welfare rights and dignity, police relations, and community needs.

She also volunteered and contributed to organizing the Catholic Daughters of Mary (Damas de María) in Chicago's Lincoln Park neighborhood.

Orlando Dávila, who later founded the Young Lords street gang, graduated from one of Jiménez's mother's neighborhood catechism classes and became one of José's best friends.

Originally, the Young Lords developed for mutual protection, recognition and reputation, in a city where their members were a mostly poor minority.

[10] City planners argued that Lincoln Park should be renovated as an inner-city suburb, in order to attract professionals and increase tax revenues, and to profit from housing turnover as lower standard properties were redeveloped.

[13] The bankers, building inspectors, and real-estate agents who supported Daley's master plan for Chicago were caught illegally redlining.

The youth of Lincoln Park became involved in property crimes such as car thefts, purse-snatchings, and burglaries, but also violent armed robberies, stabbings, shootings, and disorderly conduct, much associated with the damages of drugs.

In the summer of 1968, Jiménez was picked up for possession of heroin and was given a 60-day sentence at Cook County Jail, then called the Bridewell or House of Correction.

[17] On May 15, 1969, a group of 20 Young Lords members entered the administration building of McCormick Theological Seminary, demanding $601,001 from the institution to support their work.

[18] The Young Lords Organization also developed plans for low-income housing in Lincoln Park in an effort to prevent the displacement of Latinos.

The original Chicago Young Lords became the national headquarters for a movement with chapters in other cities with significant Puerto Rican populations, such as New York, Philadelphia, and Milwaukee.

In Wicker Park, they connected with the Latin American Defense Organization (LADO) and supported their demonstrations for a welfare-caseworkers union and for dignified recipient rights.

In Chicago, they were recruited by Chairman Fred Hampton into the original Rainbow Coalition, which included the Young Patriots and Illinois chapter of the Black Panther Party.

[21][22] The Young Lords initiated what they called "survival programs" at the Chicago People's Church and in other cities, modelled after projects by the Black Panthers.

The Young Lords conducted demonstrations for welfare dignity and women's rights, against police brutality and racism, and for self-determination for Puerto Rico and other Latin American nations.