Puerto Rico nationalist Oscar Lopez Rivera has been freed from house arrest after decades in custody.
His case transformed him into a martyr for supporters, but outraged those who lost loved ones in a string of bombings.
Wearing black jeans and a shirt decorated with a Puerto Rican flag badge, the 74-year-old grinned and waved to cheering supporters through a fence at his daughter's San Juan home before getting into a Jeep.
Escorted by the mayor of Puerto Rico's capital and other backers, he was scheduled to stop at a federal building to return electronic tags that monitored his movements during his home confinement.
Roughly 50 people congregated in the streets outside the apartment building in San Juan's Santurce district holding flowers, some embracing in tears and chanting: "Free at last."
A group of singers from University of Puerto Rico's choir harmonised as Lopez drove past.
A street celebration was expected to draw thousands of supporters later in the day.
Through a fence, Lopez told El Vocero newspaper: "If we love this country, we have an obligation to defend it."
Lopez was considered a top leader of the Armed Forces of National Liberation, or FALN, an ultra-nationalist Puerto Rican group that claimed responsibility for more than 100 bombings at government buildings, department stores, banks and restaurants in New York, Chicago, Washington and Puerto Rico during the 1970s and early 1980s.
The FBI classified the Marxist-Leninist group as a terrorist organisation.
The most famous bombing was the still-unsolved 1975 explosion that killed four people and wounded 60 at Fraunces Tavern, a landmark restaurant in New York's financial district.
Lopez, a Vietnam War veteran who moved from Puerto Rico to Chicago as a child, was not convicted of any role in the bombings that killed six people and injured scores, but those who lost loved ones hold him responsible.
"This guy was convicted of leading the FALN that murdered people," said Joseph Connor, whose father, Frank, was killed in the Fraunces Tavern attack.
While many Puerto Ricans supported Lopez as a sort of patriot and political prisoner, those seeking independence remain a small group.
The option garnered less than 6% of the vote in four referendums that Puerto Rico has held on its political status.
Puerto Rico has been under US jurisdiction since 1898, and its people have been US citizens since 1917.
The island is home to numerous military veterans, yet Puerto Ricans cannot vote for president, and their representative in Congress cannot vote either.
They pay Social Security and Medicare payroll taxes, but not federal income tax.
A campaign to free the Puerto Rican independence figure over the years has drawn support from Pope Francis, former President Jimmy Carter and Hamilton creator Lin-Manuel Miranda.
"He has his champions and his critics, but this much is true: He served a lifetime in prison, including 12 years in solitary confinement. Don Oscar will spend his twilight years on the island for which he sought independence, and this feels fitting," Miranda said in an email, referring to Lopez with the Spanish honorific of don.
Lopez is expected to be celebrated in Chicago later this week. Supporters also plan to honour him at the June 11 Puerto Rican Day parade along New York's Fifth Avenue.
Lopez was sentenced to 55 years in prison in 1981 after he was found guilty of seditious conspiracy, armed robbery, a weapons violation and four counts of interstate transportation of stolen vehicles.
A federal judge termed him an "unreconstructed revolutionary" and Lopez said Puerto Ricans should fight for their island's independence "by any means necessary".
He later faced an additional 15 years in jail after he was convicted of conspiring to escape from prison in Leavenworth, Kansas.
In 1999, President Bill Clinton offered Lopez clemency but the inmate rejected the offer because it excluded two associates who have since been released. Then in 2011, the US Parole Commission denied his request for an early release.
President Barack Obama commuted his sentence in his final days in office, along with clemency for others including Chelsea Manning, the transgender Army intelligence analyst who leaked more than 700,000 US documents.
Lopez was released from prison in Terre Haute, Indiana, and arrived in Puerto Rico in February to serve the remainder of his sentence under house arrest.
He had been staying with his daughter at her home in the capital of San Juan.
He has said that upon returning to Puerto Rico he wanted to spend time with family and create a think tank to work on issues including climate change, the economy and the island's political status.