NEW YORK -- Immigration activists took to the streets Tuesday to protest the Trump administration's decision to end the 2012 program that deferred deportations for nearly a million young people who were brought to the U.S.

Attorney General Jeff Sessions outlined the decision at the Justice Department, arguing that the Deferred Action for Childhood Arrivals (DACA) was an "unconstitutional" overreach of former President Obama's executive authority.

After the decision was announced, protesters marched in cities across the country, including Denver, Phoenix, Washington and New York City.

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In Los Angeles, some of those able to come out of the shadows because of DACA told their stories, CBS News correspondent John Blackstone reports.

Yamilex asked only be identified by her first name. She said her family came to the U.S. when she was 7 years old to escape violence in Guatemala.

"We went through so much things that a 7-year-old should never have to go," she said with tears in her eyes, "but it was all because we knew that in this country we would have more opportunities."

"Where do I go from here?" she asked.

Docmary Reyes, 21, left, a DACA recipient, joins protests in downtown Los Angeles on Tuesday, Sept. 5, 2017. Richard Vogel/AP

Ivan Ceja, now 25, was just 9 months old when his family crossed the border from Mexico.

"I know I'm vulnerable -- that's valid. I know I can be deported tomorrow but I'm not going to go down and give Trump or Sessions the luxury of seeing me defeated," Ceja told Blackstone.

In Manhattan, hundreds of activists gathered on Fifth Avenue in front of Trump Tower. At least 34 protesters were arrested, a New York Police Department spokesperson told CBS News.

A 24-year-old woman who lives and works in Manhattan said she was brought to the U.S. from Mexico when she was 4 years old. She said she's the only member of her family who was protected by DACA.

"I don't consider Mexico my home," she told CBS New York. "Home is here in New York."

Some activists cried as they held hands during a sit-in on the pavement. Others stood on the sidelines, chanting loudly and waving signs. They yelled "undocumented -- unafraid."

"DACA meant everything to me. And now, five years later, I feel like my life is back in that place, like my life is back in limbo," Angie Kim, a DACA recipient, told CBS New York.

In Denver, high school students staged a walkout to protest the decision. Students marched with signs in support of DACA and joined a larger demonstration downtown, CBS Denver reports.

"I started crying because I don't think it's fair that people think that DACA is something wrong when it's not," Maria Daniela Lopez, a DACA applicant, told the station.

She added, "Like my poster says, DACA is working and it is supporting thousands of people, so I don't think it's fair that they're taking that away from everyone."

In Phoenix, DACA recipients and their families listened to Sessions' announcement and shed tears.

"We're not just here trying to get out of class, trying to skip class, trying to skip our work. It's a movement," Omar Galindo, a high school student, told CBS affiliate KPHO-TV. "We've gotta stand up for what's right."

Aida Penuelas, a DACA recipient, told the station that she feels like her future is uncertain.

"I'm heartbroken because everything I've ever dreamed of is falling apart," she said. "My future, I don't see it anymore. Before this morning I would wake up and I could see a future ahead of me and now I don't see anything; I don't know what's going to happen."