On a quiet Friday evening, a band of grizzled but passionate prison activists wound its way through the corridors of Riverside Church, into a bright business-like meeting room. On the agenda this night: the launching of a campaign to end what they call the “New Jim Crow.”

The phrase refers to academic Michelle Alexander’s book “The New Jim Crow: Mass Incarceration in the Age of Colorblindness,” which argues that the American criminal justice system is both unjust and racist. Several city-based activists dealing with the rights of prisoners have heard of the book: more than a few highly recommend it, too.

Among those present at this private meeting were two Harlem residents who have endured the prison system for decades and survived to tell the tale.

“We do this and we live this 24/7, all day every day,” said Joseph “Jazz” Hayden, a 70-year-old organizer and activist who had been in prison for 20 years. “But others don’t necessarily know what we’re doing, or know much about the issues we’re dealing with.”

Several of those attending the meeting are associated with the Riverside Church Prison Ministry, a longstanding and well-known prison activist group which receives financial grants from Riverside Church. While the Campaign to End the New Jim Crow is committed to completely transforming what they view as a racist and damaging system of mass incarceration, the regular work of the Riverside Church Prison Ministry involves visiting and writing letters to prisoners, campaigning to strengthen prisoner’s rights, and helping the formerly imprisoned to secure employment and housing.

Common issues here especially pertinent to uptown residents include the disproportionate incarceration of African-Americans and Latinos, as well as the way in which young offenders can quickly become locked into the criminal justice system, often unfairly.

Youths from upper Manhattan account for about 77 percent of Manhattan’s total juvenile detainee population, according to the 2010 New York City Community Snapshots available online.

According to these same community profiles, in all four of the uptown Community Boards – 9 through 12 – more than 90 percent of those incarcerated are either African-American or Hispanic.

As Larry White, a 76-year-old community advocate and policy liaison for the Fortune Society, who was himself imprisoned for 32 years, puts it, “How do we transform a system that we find unbearable?”

Still, it isn’t only uptown residents who care about the rights of the incarcerated. A symposium on criminal justice last month organized by the Think Outside the Cell Foundation, which campaigns for the rights and reputations of prisoners, attracted at least 1,500 people throughout the day from all across the city to Riverside Church. Manhattan Borough President Scott Stringer and City Councilman Jumaane Williams of Brooklyn also attended.

“We remain separate and unequal on the streets of New York,” Stringer said at the event, where he spoke about the need to change the widespread police practice of stopping and searching individuals on city streets.

Stringer received a round of applause when he said: “85 percent of those stopped are black or Latino, who are nine times more likely to be stopped than whites. … We cannot wait a minute longer to have a serious conversation about stop and frisk and its collateral effects on our community.”

Asked about Chief Judge Jonathan Lipmann’s recent proposals to raise the age at which teenagers in New York are tried as adults instead of juveniles, Stringer agreed that the proposal deserved exploration. He added, “Criminalizing teenagers without an idea of what adult prison looks like is not a good idea.”

New York and North Carolina are the only two states in the nation that try 16-year-olds in adult criminal courts, rather than in family court with juvenile justice punishments.

However, some local activists and residents hold slightly more cautious views on the relationship between criminal justice and upper Manhattan specifically.

Nina Saxon, a community youth activist born and raised in East Harlem, outlined several possible reasons why younger residents of upper Manhattan may be more prone to arrest and incarceration.

“If you look at the demographics of East Harlem, including the unemployment rates, the drug incident rates, and all the arrests, along with the concentration of public housing,” she said, “it makes more sense.

“There are no jobs or training programs. Our youth don’t have any role models: we need real role models who look like us.”

Similarly, after the first official public meeting of the Campaign to End the New Jim Crow, a week after the national symposium, independent consultant Anna Barrow said: “I think people in Harlem are oblivious to these problems. They’ve come to accept these conditions as normal.

“My 36-year-old son talked with friends mostly about plans to end up in prison, instead of talking about plans for employment.

“He also said that being stopped and searched by police has happened to him at least two or three times a week, for 10 years now.”

While Saxon and Barrow are more realistic about the problems faced by uptowners struggling with the criminal justice system, they are nonetheless passionate about fixing what they see as injustices.

Saxon volunteers with the Riverside Church Prison Ministry and teaches women ages 17-62 in Manhattan’s Bayview Correctional Facility. She described the “intense” work as “one of the best things in my life.”

The apparent common factor among these prison activists, who encompass diverse backgrounds and motivations, is visible excitement about recent events, coupled with a commitment to genuine reform, if not revolution, with respect to this country’s criminal justice system.