Four years ago, Pulitzer Prize-winning journalist Jose Antonio Vargas “outed” himself as an undocumented immigrant in a New York Times Magazine essay, stunning media and political circles and attracting coverage around the world.

Ever since, he has been at the forefront of challenging the media’s coverage and society’s treatment of undocumented immigrants: He’s testified on immigration reform before the U.S. Senate Judiciary Committee and, in his 2014 film “Documented,” he shared in minute detail his own journey while closely exploring the plight of other undocumented immigrants in the United States and the politics that surround the hotly contested issue of “legal status.”

On Sept. 15, Vargas will bring those powerful personal stories to the University of Nebraska-Lincoln. His 7 p.m. lecture at the Lied Center for Performing Arts is the first in the 2015-16 Thompson Forum series, “Activism.”

Vargas will poignantly explore one of the most divisive questions facing our country: How do you define American? He will share his life story, including details of his journey to the United States from the Philippines as a child, his travels as an immigration reform activist and his reunion with his mother, whom he hadn’t seen in over 20 years.

This year’s E.N. Thompson Forum will delve into the origins of activists and the characteristics of effective social and political movements, narrated with candor by men and women who have inspired generations.

The lecture is the culmination of several events related to Vargas’ visit. At 2:30 p.m., the Mary Riepma Ross Media Arts Center will host a screening of “Documented,” followed by a short discussion of the film at 4:30 p.m.

Then, at 6:30 p.m. in the Lied Center’s Steinhart Room, Kevin Ruser, M.S. Hevelone Professor of Law and supervising attorney for the Center for Legal Immigration Assistance (CLIA), will conduct a pre-talk, “Define Nebraskan: Tales of Undocumented Immigrants in Nebraska.”

Ruser said Vargas’ appearance would be an essential contribution to the discussion surrounding immigration.

“Immigration issues are complex and often misunderstood,” he said. “The more people understand about immigration and immigrants, the better informed their discussions about these important topics will be.”

Vargas is the founder of Define American, a media and culture campaign that seeks to elevate the conversation around immigration and citizenship in a changing America. He is also working with the Los Angeles Times to create #EmergingUS, a new section focused on race, immigration and multiculturalism.

He has been a senior contributing editor at The Huffington Post, where he launched the Technology and College sections and created the Technology as Anthropology blog, which focuses on technology’s impact on people and how they behave.

Vargas also covered tech and video game culture, HIV/AIDS, and the 2008 presidential campaign for the Washington Post and was part of the team that won the Pulitzer for covering the 2007 massacre at Virginia Tech. His 2006 series on HIV/AIDS in Washington, D.C., inspired a feature-length documentary, “The Other City,” which he wrote and co-produced. The film premiered at the 2010 Tribeca Film Festival and aired on Showtime.

Lectures are streamed at http://enthompson.unl.edu and are available live on Lincoln Time Warner Cable digital channel 80, channel 71.16 without a cable box, UNL campus channel 4 and UNL KRNU radio 90.3 FM. All lectures are interpreted for the deaf and hard of hearing.

The E.N. Thompson Forum on World Issues is a cooperative project of the Cooper Foundation, the Lied Center and UNL. It was established in 1988 with the purpose of bringing a diversity of viewpoints on international and public policy issues to the university and people of Nebraska to promote understanding and encourage debate.

Vargas’ lecture is sponsored by the University Program Council.