Amanda Knox arrived at Seattle-Tacoma International Airport this evening and told cheering friends and supporters she was "overwhelmed" to be home.
"They're reminding me to speak in English, because I'm having problems with that," Knox said, her voice trembling. "I'm really overwhelmed right now. I was looking down from the airplane, and it seemed like everything wasn't real."
After she teared up during earlier brief thank yous by her parents and her U.S. legal adviser, Knox, who was freed this week after four years in an Italian prison for a murder she has steadfastly denied committing, spoke only briefly at a podium while wearing a loose gray sweater over a black T-shirt, after a supporter shouted, "Welcome Home, Amanda."
"What's important for me to say is just thank you to everyone who has believed in me, who has defended me, who has supported my family," she said. "My family's the most important thing to me right now, and I just want to go and be with them."
She took no questions and left the room with her family.
Knox's arrival in Seattle on a British Airways flight out of London capped an emotional rollercoaster for the 24-year-old woman. Her legs buckled and she nearly collapsed when the Italian court threw out her murder conviction Monday and released her from prison, where she'd spent almost four years.
Knox and ex-boyfriend Raffaele Sollecito were convicted in 2009 of killing Knox's British roommate, Meredith Kercher. Knox was serving a 26-year prison term, and Sollecito was given a 25-year sentence.
Theodore Simon, the Knox family's U.S. legal adviser, told those assembled for Knox's airport homecoming not to forget about Kercher.
"Let us not forget that Meredith was Amanda's friend, and I know Amanda and the family wants you to remember Meredith and to keep the Kercher family in your prayers," Simon said.
He added that Knox's return ended "a trying and grueling, four-year, nightmarish marathon that no child or parent should have to endure," but that Monday's Italian court decision "unmistakably announced to the world" that she was not guilty in Kercher's killing.
After Knox was hustled out of the courtroom in Perugia, Italy, crying and stumbling after her acquittal, Knox returned to Cappane prison where she received an exuberant welcome from the inmates.
"All the prisoners, 500 or 600 of them, started to greet Amanda from the windows, like soccer stardom," Corrado Maria Daclon, secretary general of the USA Italy Foundation, told ABC News. "It's difficult to describe the happiness of them seeing Amanda and greeting her and seeing her free now -- yelling, 'Oh, wow, ciao Amanda!' It was really, really incredible emotion."
Daclon said Knox walked back into the prison through its central square, surrounded by blocks and blocks of prison buildings with small windows. Two to three prisoners crammed into each small window, cheering and waving clothing in the air, as if they were flags.
"All the prison was greeting her like a champion," he said.
An elated Knox returned the greeting.
"She was moved and jumped two times to greet them. She was so touched, you can't imagine," Daclon said.
Daclon said he engineered Knox's departure from the prison, an overnight stay near Rome and getting her to plane under the radar of the media.
"The foundation had been working on the plans to get Amanda out of jail for 20 days, carefully studying how to get her out of jail, her arrival in Rome, transfer to the airport, her arrival and transit through nonpublic area of the airport," Daclon said.
The last leg of the departure plan, he said, was "a 12-man police escort to get her through the airport." He said the operation was dubbed "Return to Freedom."
Corrado accompanied Knox out of the prison and into a waiting car, which took them through a swarm of 100 paparazzi, he said.
"We had a very fast car. ... It was just us two and driver in the car," he said.
They were trailed by a convoy of paparazzi on motorcycles, so they sped off on a country road, changing directions several times until they lost the media. Once they were alone on the road, they headed for Rome.
"We met up with the rest of the family along the way," Daclon said. About 15 family members and friends accompanied Knox to Rome.
"She spent the night in a protected place. It was not a public place, in the area of Rome. Not a hotel as she would have been discovered immediately when she had to hand in her passport to be registered," he said.
Knox and her mother, Edda Mellas, stayed together while the rest of the family registered at a hotel. Daclon picked up Knox again this morning at 8:30 a.m. and headed for the airport.
Knox thanked Daclon and her supporters in a letter released today.
"To hold my hand and offer the support and respect through the barriers and controversies of the Italians. There was the Italy USA Foundation, and many who have shared my pain and helped me to survive on hope," Knox wrote.
"I am forever grateful for their caring hospitality and their courageous efforts. Those who wrote to me, who defended me, who stayed close to me, who prayed for me. We are forever grateful. I love you. Amanda," the letter read.
ABC News' Suzan Clarke and Mark Mooney contributed to this report.