Chelsea Manning says she was trying to 'do the right thing' when she leaked classified military information Manning wanted to spark a debate about our country’s military actions overseas.

 -- Chelsea Manning said she leaked hundreds of thousands of classified military documents – a move that would eventually lead her to serve the longest prison sentence of any leaker in U.S. history – because she wanted to spark a public debate about our country’s military actions overseas.

“My intention was to draw attention to this … and do the right thing,” Manning told ABC News' Juju Chang in an exclusive interview for a special edition of “Nightline.” “And I struggled with that, but the intention was very much like, ‘This is about improving the country. This is about improving our standing in the world, this is about improving everything.’ And maybe this can start a debate on that.”

In the summer of 2013, Manning was convicted by a military tribunal under the Espionage and Computer Fraud and Abuse Acts and sentenced to 35 years in prison for releasing nearly three quarters of a million documents to WikiLeaks. Manning at that time was a 22-year-old United States Army private named Bradley Manning.

“I was driven to stay in the military and to do my job, to do the best possible job I could. And then I found that everything was far more complicated and far messier than I ever imagined,” Manning said. “I was always willing to accept responsibility for those decisions … my intentions were pure and clean.”

At her court martial, Manning had pleaded guilty to some of charges, without the protection of a plea agreement. She was convicted of 17 of the 22 charges against her but acquitted of “aiding the enemy.” The latter charge is akin to treason and punishable by death or life without parole.

When asked if she regretted leaking classified information, Manning said, “I don't want to retroactively impose things on me.

“All I can say is that, you know, I accept a responsibility,” she continued. “I went through a decision-making process that I don't think I would have done anything differently if I went through and played it again because -- not because I'm retroactively imposing that on me, but because I would have been a different person. And I am a different person now.”

David Hammond, who described himself in an interview with ABC News as “the only lawyer that Chelsea did not choose to represent her” but was assigned to her “by the U.S. Army,” also pushed back against labeling her as a traitor.

“The military judge clearly didn't buy the prosecution's theory that she intended to aid the enemy,” Hammond said. “You could cry out that Chelsea Manning is a traitor [but] from a legal perspective it's flat out incorrect.”

Manning served seven years at the at the U.S. Disciplinary Barracks at Fort Leavenworth, Kansas, until President Barack Obama in January commuted the majority of her sentence after her appellate legal team, Nancy Hollander and Vince Ward, made the request the previous fall.

Manning told “Nightline” she found out about her commutation from a breaking news crawl on television in prison: “It said, you know, ‘President Obama commutes Chelsea Manning's sentence.’ And I'm like, ‘OK’ ... I freaked out before I celebrated, because I'm like ... ‘Is this really going to happen? Is this real? Am I imagining this?’”

Hollander recalled the moment she found out Manning’s sentence was commuted.

“I got this call from my receptionist, through my office phone saying, ‘The White House is on the phone,” Hollander said. “The voice on the other end said ... ‘This is the counsel for the president … The president has commuted your client's sentence and is going to announce it in two minutes.’ And I just screamed. I screamed. ‘Oh my God.’ I just screamed ... ‘Does Chelsea know?’ And he said, ‘We're getting the information to her now. You might want to turn on your television.’”

Even now, Manning claims she has “nothing but utmost respect for the military” adding that “the people who are in the military work very hard, often for not much money, to make their country better and to protect their country. And I have nothing but respect for that. And you know, that's why I signed up.”

Manning entered active duty status on Oct. 2, 2007. She was an intelligence analyst assigned to HHC, 2nd Brigade Combat Team, 10th Mountain Division at Fort Drum, New York.

At that time, she was living as an openly gay man.

By enlisting, she followed in her father’s footsteps, who joined the Navy at age 19 and was also trained as an intelligence analyst.

“I would come home every day and I would see on the television, the surge in Iraq … Iraq descending into chaos,” she recalled. “With these images from Baghdad every night, I felt like maybe I can do something. Maybe I can make a difference.”

But while she felt “a call to duty,” she said she was also “really struggling with gender.”

In October 2009, Manning arrived at FOB Hammer, an isolated military base located 40 miles east of Baghdad, Iraq.

“We’re in a big, plywood box that's an office ... and it's dusty ... I've got 30 to 50 colleagues, all in this small, confined space,” she said describing her work conditions.

They were flooded with data or as she put it, “We're drinking from a fire hose. We're getting all this information from all these different sources and it's just death, destruction ... we're filtering it all through facts, statistics, reports, dates, times, locations.”

“And eventually ... I stopped seeing just statistics and information. And I started seeing people,” she continued. “And I started connecting that with, ‘Oh my God, this is a country in which there's all this stuff happening.'”

The classified files that Manning ultimate leaked indicated, according to one of the four briefs filed in Manning’s appeal, “U.S. authorities knew about widespread torture and ill-treatment of detainees by Iraqi forces, yet transferred thousands to Iraqi custody between early 2009 and July 2010, in violation of U.S. obligations under the U.N. Convention against Torture and other treaties. An order known as "Frago 242" issued in June 2004, barred coalition troops from investigating any violations committed by Iraqi troops against other Iraqis.”

Manning specifically pointed to a video she leaked that eventually was dubbed by WikiLeaks as "Collateral Murder," as an example of something she felt needed should be made public.

“It's everything that you need to know about warfare is right there in one spot, in one 47-minute video,” said Manning. “Counter-insurgency warfare is not a simple thing … it's not as simple as, like, good guys versus bad guys. It is a mess.”

“There are thousands and thousands of videos like that,” she added.

The video showed the July 12, 2007, Apache air strike killing of unarmed Iraqi civilians and two Reuters journalists as well as wounding school children. When WikiLeaks released the video in April 2010, it generated a cloud of suspicion due to the Pentagon’s unwillingness to release or confirm its existence despite Reuters’ repeated requests for two years under the Freedom of Information Act (FOIA). Former infantryman Ethan McCord, who rescued the wounded children, would later publicly praise Manning as a “hero.” Manning told “Nightline” she leaked the video not only for the American public to see it but “for history to have that.”

Although Manning sent over 700,000 government documents to WikiLeaks, she was charged with leaking secret portions of only 227 documents under the Espionage Act. The information she disclosed included low level battlefield reports from Iraq and Afghanistan, evidence of civilian deaths in Iraq and Afghanistan, Guantanamo prison camp detainee profiles and U.S. diplomatic correspondence.

In Manning’s 250-page appeal, which is still ongoing, her legal defense team compared her case with that of General David Petraeus -- one of the most decorated Army generals in American history and the former director of the CIA. Her team noted that Petraeus pleaded guilty to disclosing highly classified information to his former mistress and biographer. Her lawyers emphasized that Petraeus disclosed information that was far more sensitive than anything Manning leaked and yet he pleaded guilty to a misdemeanor offense and was sentenced to two years of probation.”

“Five years ago I made a serious mistake. I acknowledged it. I apologized for it. I paid a very heavy price for it, and I've learned from it," Petraeus said in an exclusive interview on ABC's "This Week” in December 2016.

Rick Ledgett, former deputy director of the National Security Agency, defended Petraeus in a June 1 interview with "Nightline," saying “he went through a criminal process,” adding, “One of the things that factored into that was the contributions that he had made over a career to the national security of the United States. I think that was factored in. I think that's appropriate to factor in.”

Ledgett criticized Manning at the time for not pursuing legal options inside the system: “She could have gone to her commander. She could have gone to the judge advocate general. She could have gone to the Department of Defense inspector general ... to her congressional representatives, either the Armed Services Committee or her home representative.”

But Manning pushed back on that.

“Everybody says that there's channels ... but they don't work,” she said. “We've seen for at least a decade now that when you have information and you see wrongdoing, you don't have safe channels to go to ... They exist on paper, but in practice time and time again, you've seen that these channels don't work.”

In his interview, Ledgett also described Manning’s actions as arrogant saying she couldn’t not have possibly known the impact of her documents on national security due to “A) from the amount of time she had to go through the documents, and B) from an experiential base to judge whether, in fact, there was going to be harm -- or not.”

Manning’s response to that is the information she leaked did not reveal sources, methods, current or future operations. She characterized it as “historical data.” She felt sure it would not impact national security because, as she put it, “I work with this information every day.”

Robert Gates, who was then Secretary of Defense, commented on the impact of her leaks at a Nov. 30, 2010, press briefing: “Now, I’ve heard the impact of these releases on our foreign policy described as a meltdown, as a game-changer, and so on. I think those descriptions are fairly significantly overwrought ... Consequences for U.S. foreign policy? I think fairly modest.”

Manning claims that her mental and emotional struggles associated with gender dysphoria did not have an impact on her leaking. Yet, in her appeal, her lawyers state it as a mitigating factor. Manning dismisses that as a “legal strategy” stressing that she does not feel it was a “significant factor.”

However, while stationed in Iraq, Manning wrote an email dated April 24, 2010, to one of her commanding officers. She attached a picture of herself dressed as a woman and explained: “This is my problem ... I thought a career in the military would get rid of it ... it’s not going away, its haunting me more and more as I get older. Now, the consequences of it are dire, at a time when its causing me great pain in itself.”

A few weeks later, Manning was arrested in Iraq for disclosing information to WikiLeaks. After her arrest, she was transferred to a U.S. military base in Kuwait, and then to the Quantico Marine base in Virginia. After being held in solitary confinement at all three locations, Manning was then transferred to the medium-security military prison in Kansas to await her trial.

Manning’s emotional and psychological turmoil was exacerbated by the 9 months of pre-trial solitary confinement. The U.N. special rapporteur on torture accused the U.S. government of cruel, inhuman and degrading treatment toward Manning. Her solitary confinement is one of the main bases of her ongoing appeal.

“Our first appellate issue is the fact that Chelsea was held in solitary confinement ... while she was awaiting trial,” said her attorney Vincent Ward. “Another thing that gets lost is her treatment ... She was bullied and mistreated by the guards while she was in solitary confinement. She was made to do humiliating things, stand in front of the guards completely naked ... If she was reading a book and she took her eyes off the book they would take the book away from her.”

Manning described her confinement to "Nightline" as a "mind game."

“So you're sitting in a room by yourself,” she said. “I've got two Marines watching me at all times. I'm sitting up straight. I can't lay down from 5 a.m. until 7 p.m. I can't sit down, I can't lay down. I can't lean back on anything. I'm sitting upright. Sometimes have my glasses. I sometimes don't. I don't have much clothing. I hear every single sound in the entire place. The drips of water, the sounds people's footsteps, the sounds of- chit-chat in, off in the distance from the guards. It was a very empty prison.”

Manning finally came out as a trans woman, Chelsea Elizabeth, on Aug. 22, 2013, the day after her sentencing. She sought hormone therapy as part of her transition during incarceration. The military denied her request. The ACLU, led by trans lawyer Chase Strangio, sued the Department of Defense in September 2014 over its refusal to provide Manning medical treatment for gender dysphoria. After over a year of litigation, the military relented and began Manning’s treatment with hormone therapy. She made history, becoming the first person to receive health care related to gender transition while in military prison.

Manning told “Nightline” she fought for her hormone treatment behind bars because “it’s literally what keeps me alive.”

When asked to respond to those who feel that taxpayers should not be paying for these treatments, she said, “Health care is something that prisoners have a right to, you know? They don't get to pick and choose whether or not you get this health care plan and this health care plan. It's provided to you by the prison. The prison has a responsibility to provide you with necessary health care, and trans health care is necessary ... because if we don't get our treatment, we die.”

Ward, her appellate lawyer, explained to “Nightline” that Manning’s litigation and her struggle for access to treatment at Fort Leavenworth was one of the major reasons that she eventually attempted suicide twice and made it urgent to petition Obama for clemency.

“Leavenworth is a male prison,” he said, but “Chelsea's not male ... No one would refer to Chelsea as ‘she’ or by ‘Chelsea.’ Right? People would at best refer to [her] as ‘Manning.’ It was like she wasn't a man or a woman.”

Manning described the despair that drove her to try to take her own life more than once when she was behind bars.

“You just want the pain to stop,” she said. “The pain of not knowing who you are or why you are this way. You just want it to go away ... you're just caught up -- so caught up in this dark blackness inside yourself that the rest of the world doesn't matter.

Chace Strangio, her ACLU lawyer who spearheaded her litigation, recalled his phone call with Manning after the military made its final decision to continue to subject her to the forced haircuts that she endured for her entire incarceration.

“She was subjected to male standards, held in a male facility, even though she's a woman,” he said, and “she had, you know, this deep pain about what it felt like to exist day in and day out, not just in the physical prison of the USDB [the United States Disciplinary Barracks on Fort Leavenworth in Kansas], but in this world in which her dignity as a woman, as a human being, was constantly being attacked.”

In transitioning to becoming a woman, Manning said the length of her hair in prison was very important to her.

“It's the first thing that people see,” she said. “I wanted to have medium-length hair ... it’s not costing the government anything for me to grow my hair.”

She credits the kindness of inmate barbers for making it easier.

“I had an inmate barber that helped me get through that ... I had a couple of them, actually, over time, and he took care of me,” she said. “He shampooed my hair, he cut my hair with scissors, made it a relaxing process ... the inmates really made it less of a painful experience for me.”

Manning said she plans to continue with her hormone therapy, which the military will not be paying for. “I have a private health care plan,” she said. The importance of affordable health care is a topic Manning has written about in op-eds as well as in her tweets.

Manning set up her Twitter account, and then an Instagram account, @xychelsea in response to the thousands of letters she was getting, especially from trans-children.

“It was just to connect with people and make them realize that, you know, like, ‘Hey, I'm getting your letters. I just can't write to, you know, 15,000 people,’” she explained.

Christina DiPasquale, founder and CEO of Balestra Media who started working with Manning three years ago, described how Manning would “tweet” from prison.

“She would actually think of her tweets and dictate them over to the phone to a supporter or a volunteer, who would post them for her, and read to her some of the reactions,” DiPasquale said. “She would tell them to re-tweet someone or to look for a particular tweet or a comment.”

Manning personally posted her first photo as a woman upon her release from military prison on Instagram.

“Owning my identity ... ties into my value of dignity,” she said. “I think that every person has, you know, whether trans, you know, gay, straight, black, white, Asian, Hispanic, you know, we all have the right to define ourselves and to define who we are ... without any judgment or expectations placed on us.”

Her definition of freedom is “just being able to express myself for who I am," she said. "And there's no expectations on me. There's no rules that I need to follow. I can be who I want to be and I am who I am.”

Manning has nearly 300,000 followers on Twitter and Instagram, but doesn’t really see herself as a public figure.

“I don't see it as celebrity,” she said, “It’s just what I was doing on social media as a teenager, just scaled up by several orders of magnitude.”

When asked about how she deals with hateful comments on social media, she said, “I just remember that ... sometimes people have reasons of doing that that have nothing to do with the content. It's just, like, a part of ... their needs to be heard in the world and to have a connection to people, even if it's negative.”

Manning has received financial support from donors who do not know her. Singer-songwriter Evan Greer organized an online benefit album, entitled “Hugs for Chelsea,” which was compiled by a group of prominent musicians to show their support and raise funds to cover Chelsea’s living expenses as she transitions out of prison. She said they have raised around $12,000 from the album plus $173,000 through Manning’s GoFundMe that Strangio and Greer organized.

Manning said she is grateful for their support and said, “It's incredible to have the opportunity to be able to defend myself.

“It's incredible to have the opportunity ... to not have to worry about certain logistical things,” she continued. “And all of that is based upon just the fact that people are going outta their way. And it's usually small amounts. It's not like I have these major donors or anything. ... This is just enough to get through this process.”

In an interview with ABC News, Greer emphasized the role activism played in freeing Manning: "President Obama commuted Chelsea's sentence, but it was grassroots activism that set her free -- and likely saved her life. Hundreds of thousands of people from across the political spectrum came together to fight for Chelsea because we could see that she was fighting for all of us. In the end, a scrappy band of activists with little more than laptops, online savvy, protest signs, press releases, creativity, and hope managed to change the course of human history. We refused to allow Chelsea Manning to disappear. By raising our voices together, we raised so much public awareness and built enough political power that the President of the United States felt like he had to respond. The story of Chelsea Manning's freedom is a story of ordinary people who have done extraordinary things, and that's a story that people need to hear now more than ever."

Manning said she has not yet spoken to Obama, but said she would to tell him thank you.

“I’ve been given a chance. That’s all I wanted,” she said.

Her lawyer, Hollander, agreed.

“You will always hear that the military says, ‘We take care of our soldiers. We never leave a body on the ground. We never leave anyone behind. We take care of our soldiers,’” Hollander said. “The only person in the entire military who ever took care of Chelsea was her commander-in-chief, President Obama, when he commuted her sentence. That was the first time anyone ever took care of her as a service member.”

Manning, an avid reader and writer, is a “Game of Thrones” fan. However, there was one book, “Wild” by Cheryl Strayed, which she said helped her more than any other.

“I'm not a perfect person. I've made mistakes. I've learned from stuff,” Manning said. “I relate with her [Strayed], because she just lays it all out there. It's raw.”

As for what she plans for in the future, Manning said, “I'm going to figure that out.”

“I'm going to find my place. I'm going to find out what I can do, what am I good at -- what's available as an option,” she added. “I haven't even moved into my apartment yet fully ... I don't know where this road's going to lead me ... I'm at a fork in the road right now and I haven't decided which path to take.”

ABC News' Lauren Effron contributed to this report.