NFL player Michael Vick is now an author.

Vick, quarterback for the Philadephia Eagles, will come out with his biography, "Finally Free," published by Worthy Publishing. He started writing it when he was in jail for 21 months in Leavenworth, Kansas. He also has a new clothing line, "V7," acknowledging his sins with T-shirts that read, "It's not how you start, it's how you finish."

In an interview with USA Today, Vick, 32, said he is "free to do whatever I want to do, and I couldn't ask for a better life right now." He has accepted that his dogfighting past holds a permanent place in his legacy.

"I've made peace with it, because I have no control over it. It's not like I could do it all over again," he told USA TODAY Sports. "But at the same time, I think I made a lot of changes for the better and I think in my quest to be an advocate against dogfighting and working with the Humane Society, I've helped more animals than I've hurt, and I continue to do that."

Vick says he wrote the book to help others who have made serious mistakes but also to reclaim the narrative of his life, to "tell it my way." Bored in prison and looking for a way to pass time, Vick said he wrote 70 pages in one day.

"People are always going to have their opinions and feel the way that they do," he says in an interview. "You can't change it. The reason I'm writing this book is so people can have an understanding and not just go off of what they see on TV or what they heard, the picture that's been created."

The book also describes his turbulent childhood, rise to stardom, and events surrounding his 21-month prison sentence on federal dogfighting charges.

Vick admitted, "I became better at reading dogs than reading defenses."

Tony Dungy, author of the book's foreword, wrote, "Finally Free tells an amazing story. It's not pretty, but it's real. If you're like me - if you've ever done something in your life you wish you could take back, it will encourage you to learn that we serve a God of second chances and live in a country of second chances," according to the book's website.

USA Today posted excerpts of the upcoming book:

• "Back when I was involved in those activities, I may have become more dedicated to the deep study of dogs than I was to my Falcons playbook (Vick played in Atlanta from 2001-06). I became better at reading dogs than reading defenses. That's just so sad to say right now, because I put more time and effort into trying to master that pursuit than my own profession ... which was my livelihood ... which put food on the table for my family."
• "It was a very nervous time for me. I knew I was going to try to lie my way through the whole dogfighting case and see if money, good lawyers, and manipulating the system could get me out of the position I was in -- which was a terrible position."
• "'Babe, let's go back,' Kijafa Frink (Vick's then-fiancee, now his wife) would say over and over. 'Let's run away.' When we pulled up to the courthouse, Kijafa looked me dead in the eyes. 'Don't go,' she said. 'Don't leave.' Then she started crying. ... Then I started crying. The pain they felt -- it was all my fault."

• "I wanted to make real tangible and positive changes on behalf of animal welfare. The trip to Congress is another step toward fulfilling my promise to help more animals than I hurt."
• "My story is not finished. I have more to do. I have something that I want give back to everyone that supported me. Here it is: I am committed, focused and determined to win a Super Bowl with the Philadelphia Eagles. This is my promise. It is my drive. I will work like a champion to get there. I want to do it for my family, friends, mentors, coaches, teammates, and fans. I want to do it for Philly."

"Finally Free" will hit bookshelves Sept. 4, 2012.