18-year-old who spent nearly 13 years in foster care adopted into forever home

"I was happy that I could let go of my past," Carson Petersen told ABC News.

— -- Carson Petersen was all smiles last month after his adoption was made official in a California courthouse.

Petersen, 18, from Fresno, finally found a forever family with his foster parents, Tex and Renee Petersen, after spending over a decade in and out of the foster system.

"It was emotional," Carson Petersen told ABC News of the June 30 adoption. "I teared up a little bit because I was happy that I could let go of my past and start forward from that day, until now."

Carson first entered foster care when he was 3 years old, after his mother took her own life. At 8 years old, he was placed in the care of his biological father, and at 11, after being homeless for several years, he was placed back in foster care.

He said he found himself "going down the wrong path" in his early teens, experimenting with drugs and alcohol. But when he met Tex and Renee Petersen, he said, his life took a turn for the better.

"They were loving. They were a Christian family. They never gave up on me," he added. "We always did things together. They always called me son. They introduced me as their son to everybody. They never said 'foster son,' which was pretty awesome to feel wanted and appreciated."

"It was whatever he [wanted]," Tex Petersen told ABC News. "The main thing was that he [knew] that this was his home and that if he ever wanted us to adopt him, that it was something we would do. For me, I really don't feel much different. I've always looked at him as my son."

"It's the sign of a journey coming to an end and finally having a forever home," he added. "All too often, these kids don't have a picture hanging on the wall of their own, they don't have their own drawer ... Whatever home they were broken from is their normal. For them to come in, to be bouncing from home to home with a trash bag of their clothes, it's devastating to me."

On June 30, Carson was adopted by Tex and Renee Petersen at the Fresno County Superior Court, surrounded by family and friends.

"Carson, he's a really good young man. He loves to help people, and that's what I think I love about him most," Renee Petersen told ABC News. "I'm just so proud that we finally can make it official. It was so important for him to know that he has a mom and dad who will do anything for him and he has a home that he can always come to, and I am so glad that we were able to give that to him."

Carson recently changed his last name to Petersen and received a tattoo with his brother Hunter Petersen, also 18, the Petersens' biological son, to symbolize their bond.

Their younger siblings Kaylynn, 4, and Joshua, 2, were also adopted by the Petersens.

"I know a lot of kids in foster homes, including my [biological] brother, and they're losing hope," Carson Petersen said. "Most of them want to quit. Some of them want to commit suicide, and I strongly encourage them to keep fighting. You just got to have your faith and keep holding on to what you believe in."

Carson Petersen said he is looking forward to making memories with his family and having a place to call home.