It was a time of deep unrest, with growing criticism of the nation's involvement overseas and concerns about discrimination at home.

The University of Pennsylvania felt compelled to hold a series of campus-wide discussions and debates to try to help the nation and campus find a way through those thorny times.

That was nearly 50 years ago, during the civil rights movement and the Vietnam War.

Now, Penn, seeing a nation equally in torment, confronted by a lack of trust in the age of "fake news," and sorely divided politically, will once again open its doors wide for only the second "teach-in" in the Ivy League university's history.

The five-day series of more than 30 panels, lectures, exhibitions, and film screenings will cover topics including race, immigration, the future of technology, sexual harassment, and firearm violence. It begins Sunday and runs through Thursday. The sessions are free and open to the public, and are expected to draw hundreds of students and faculty.

"We're in a pretty contentious period," said Wendell E. Pritchett, Penn's provost. "We're trying to figure out where we want to go as a country. Institutions of higher education are important places for that conversation to happen. We want to play a leadership role in that conversation."

More than 100 faculty, staff, and students across the university's 12 schools were involved in planning the event, said Santosh S. Venkatesh, an electrical and systems engineering professor who chairs the university's faculty senate. More than a year in the planning, it's the largest campus-wide educational undertaking that Venkatesh can recall in his 31 years at Penn, and is bigger and longer than the first teach-in, March 4, 1969.

"We haven't done anything like this in more than half a century, and nothing of this level," he said.

The sessions will cross disciplines and schools, delve into the role of the academy, and explore "the production, dissemination, and use of knowledge," he said.

"What goes on in the academy is viewed with great suspicion today," he said. "We need to begin a conversation to get to common ground. It seems entirely fitting that we attempt to create an engagement, or bridges, with the larger public."

Venkatesh said he and others on the committee have reached out to city officials, legislators, and congressmen about attending the events, as well as schools around the city, Rotary Clubs, and other groups.

He's not sure how many people will attend. There's no registration requirement, but those interested have been asked to click on a link on the website. So far, about 350 have done so, he said.

Regular classes will remain in session, but the faculty senate is encouraging professors to have their students attend the events or attend as a class, he said.

Ira Harkavy, a longtime Penn employee who is founding director of the Netter Center for Community Partnerships, was a Penn student at the time of the first teach-in, called a "Day of Conscience." He said it followed a multi-day sit-in held by Penn students who were concerned about the role of research at Penn. Students wanted it to focus on "the betterment of human life" and the university's relationship with and responsibility to its surrounding neighborhood.

About 1,200 students participated, Harkavy said.

"It helped make students more conscious, more reflective about their own education, and what they wanted to do after they finished their education," he said.

He's pleased with the university's decision to hold another one, especially its efforts to reach out to the community.

"The most difficult problems can't be solved by universities alone," he said. "They require working with and learning from the community you're a part of."

One of the first sessions will explore the teaching of race.

"We wanted to kick this off with something contentious," Venkatesh said.

Later will come a discussion on "vaccine denial," looking in part at allegations that vaccines are causing an uptick in autism and the threat posed by those concerns to the eradication of disease.

With the nation still reeling from 17 shooting deaths at a high school in Florida and student protests planned over the next week, another session will focus on firearms.

"We've already made a decision to live in a world with guns," Terry Richmond, a professor of nursing, said on a video promoting the teach-in on Penn's website. "Since we've done so, let's figure out how to do so more safely."

But there are also some lighter sessions, like an "augmented reality scavenger hunt," a walk through time down Locust Walk, the main thoroughfare through campus, crafted by the biology department and School of Design, with robots along for the stroll, and a bioethics film festival exploring the promise and peril of technology.

The teach-in will begin Sunday with a family-friendly "afternoon of learning and fun" at the University of Pennsylvania Museum. A student-led discussion on the purpose of a Penn education will help to wrap up the event.

What could come out of the session is uncertain. Pritchett, the provost, said he anticipates new roles for students, a research agenda, and other initiatives.

"We are under no illusion that we are going to solve any problems tomorrow or the day after," Venkatesh said. "These are large societal questions. It seems that not making an attempt was not permissible anymore. We have to try."