Ilan Grapel, 27, arrived at Kennedy Airport looking tired and thin, but wearing a huge smile.
He said that after spending more than four months behind bars in Egypt, he had a new appreciation for the American legal system.
"All of a sudden, the Bill of Rights is not something for the history books," he told reporters gathered in the terminal.
Grapel, who holds joint U.S. and Israeli citizenship, was volunteering for a group aiding Sudanese refugees in Egypt and staying at a youth hostel when he was detained by police who saw him carrying a protest sign at a rally on June 12.
He was accused of spying for Israel, then held for months without formal charges or a trial while U.S. and Israeli officials worked to gain his release.
Grapel said he was no spy, although he does have the type of resume that makes intelligence services drool. The high achiever graduated early from Johns Hopkins University, speaks fluent Arabic and Hebrew, served in Israel's armed forces and had internships with Israel's high court and in the Queens district office of U.S. Rep. Gary Ackerman.
After Grapel's joyful reunion with family members at the airport, Ackerman said the student was more like "the kind of kid who might have been at Zuccotti Park," referring to the plaza that is home to New York City's Occupy Wall Street encampment.
Israel has also denied that Grapel was a spy.
Grapel said he was kept in solitary confinement during his imprisonment, but was treated and fed well, and allowed a visit from his mother, Irene.
"I can only say that for four and a half months, we were heartbroken," she said after accompanying her son home Saturday.
Grapel was released was from jail Thursday. He traveled to Israel, where he said he was given a hamburger and red wine by Prime Minister Benjamin Netanyahu, and then departed for the U.S. early Saturday morning.
The Delta flight was delayed for several hours due to a mechanical problem, and was nearly canceled until the flight crew voted to work extended hours just so Grapel could get home, he said.
Grapel thanked Ackerman for lobbying Egypt's ruling military council for his release. He said it wasn't the first time the congressman had written him a recommendation, but he never thought he'd have to recommend that he wasn't a spy.