With its 200-year-old stone walls in a permanent state of photogenic ruin, Eastern State Penitentiary can seem like a relic from the distant past.

But it functioned as a state prison up until 1970. And when it reopened as a museum in the '90s, its mission statement included serving as a forum for discussing current issues in criminal justice.

"Ten years ago, I would've told you we were living up to that," said Sean Kelley, director of interpretation and public programming. "But it became clear over time that we weren't doing enough."

That will change starting Friday, when visitors will be confronted not just with the ghoulish past, but with the grim present, as Eastern State opens the first major museum exhibition about mass incarceration in the United States.

Called "Prisons Today," the three-year, $360,000 exhibition addresses one of the fundamental contradictions of the modern U.S. prison system: The number of people locked up in state and federal prisons has grown from 200,000 in 1970, when Eastern State closed, to more than 1.5 million today. Yet the violent crime rate is about the same.

"The pattern is jaw-dropping," Kelley said. "Mass incarceration isn't working. We're statistically no safer today than we were in 1970. It's not working, so what's next?"

In 2014, Kelley and his team broached the issue with visitors by adding a new structure in the prison yard: The Big Graph, a monumental, 16-foot-high bar chart tracking the explosive growth and racial disparity in the prison population.

Now, they're taking the next step: interpreting those numbers for visitors. It was scary for a conservative institution like a museum, so early versions of the exhibit merely pondered the questions: "What are prisons for? And are they working?"

But as Kelley spoke with more experts, he learned that debate was already over.

"This is something that academic researchers have had a near-consensus on for quite a while now," said Nazgol Ghandnoosh, a research analyst at the Sentencing Project, a nonpartisan think tank, and an adviser on the exhibit. "But the issue had been really politicized. Now, it's a different landscape. Institutions like museums are more willing to take a bigger step in how they talk about these things."

Through art installations, informative wall panels, video displays, and interactive panels, the exhibition underscores the policies that led to this situation and highlights the human impact.

It tracks the political rhetoric, as seen in a video timeline that begins with the tough-on-crime-talk of the 1970s, '80s, and '90s (clips of Presidents Richard Nixon, Ronald Reagan, and Bill Clinton) and slowly shifts to calls for reform from both sides of the aisle (Clinton again, as well as House Speaker Paul Ryan, Grover Norquist, and the Koch brothers).

It also asks visitors to consider their own crimes and how their upbringings affected their likelihood of being locked up. An art installation by Troy Richards, The Criminal Us, invites them to leave a confession: Often, placed side by side with confessions of prison inmates, they're indistinguishable.

And it delves into serious policy questions: What is the rationale for locking people up, and what should it be? Different countries' systems favor deterrence, incapacitation (that is, preventing future crimes), retribution, or rehabilitation. The U.S. - the most carceral country in the world by a large margin - is joined by Cuba and Russia in favoring incapacitation.

Kelley wants visitors at least to understand that policies, not a rise in criminal behavior, has driven the growth in prison populations.

It's the largest and most ambitious exhibit in Eastern State's history.

Just renovating the building to house it - a series of solitary exercise yards turned into prison workshops that had long been sealed off and left to deteriorate - cost $400,000, said Sara "Sally" Elk, the museum's chief executive.

But it was a key step as the museum, which attracts 200,000 visitors a year, embarks on a strategic plan. Other items on the agenda include whether and how to restore more disused spaces: a building for offices, and an auditorium that could host lectures and events.

Now that the museum is finally functioning in line with its mission statement, she said, "We're at a point where we need to make some decisions about the future."

Seth Bruggeman, a Temple University historian who had criticized the museum's failure to address contemporary criminal justice issues, recently wrote a letter nominating The Big Graph for an award.

"For many years, ESP's preservation mission enabled a kind of historical amnesia. Visitors could, if they chose to, appreciate the 'preserved ruin' as just a ghostly trace of a distant past. The Big Graph shatters that illusion," he wrote.

With its new programming, Eastern State is now "a model for reimagining how historic sites and museums can engage audiences around the issues that bear most dramatically on the future of our nation."

But it risks alienating visitors who have come to see Al Capone's cell or hear old prison lore.

It may be the first time visitors to Eastern State - the vast majority of whom are white and tourists to Philadelphia - have considered issues like the collateral impacts of incarceration, or how a person's race might affect his likelihood of getting locked up.

So, much of "Prisons Today" is about humanizing this issue.

To that end, Kelley invited Gabriela Bulisova, a Washington photographer, to make a series of short films about individuals involved in the state system, from Corrections Secretary John Wetzel to Dawan Williams, a former inmate and an activist to a lifer named Phil, who works on restorative justice in prison, and whose face and full name are obscured, as required by state prison rules.

"We've been putting people away from their families, their communities, for a long time," said Bulisova. "Whether it's children with incarcerated parents, or parents coming out of prison, or family members stepping in to replace the incarcerated individual, they all have really compassion-inspiring, human stories."

Eastern State is also experimenting with another way to humanize the issue. They've hired four people as tour guides who have done time in prison as part of a pilot initiative running through June. Their stories are even part of the "Prisons Today" exhibit. Three of them lent objects they brought out of prison; a fourth had gotten rid of everything from that period of his life and is represented by an empty vitrine.

"We're nervous about the voyeuristic quality of it, and about what it's like to pay someone to talk about a very painful experience five days a week," Kelley said. "But being able to shake someone's hand who's been through this experience sometimes does more than all the exhibit panels and all the videos we could ever make."

"Prisons Today: Questions in the Age of Mass Incarceration" at Eastern State Penitentiary, 2027 Fairmount Ave. Hours: Daily, 10 a.m. to 5 p.m. Admission: Adults, $14; seniors, $12; students and children, $10. Information: 215-236-3300 or easternstate.org