Updated 7:26 P.M.
Many Puerto Ricans are celebrating after President Barack Obama announced he has commuted the sentence of 74-year-old nationalist Oscar Lopez Rivera.
Lopez Rivera served 35 years at the federal penitentiary in Terre Haute, Indiana.
Puerto Ricans have long demanded the release of Lopez Rivera, who was sentenced to 55 years in prison for his role in a violent struggle for independence for the U.S. island territory. His release was opposed by a national police organization, among others.
Lopez Rivera belonged to the ultra-nationalist Armed Forces of National Liberation. The group claimed responsibility for more than 100 bombings at public and commercial buildings during the 1970s and 1980s in U.S. cities including New York, Chicago and Washington. Lopez Rivera was the last of the group still in prison.
Lopez' attorney, Jan Susler, told The Associated Press she broke the news to him Tuesday and he was extremely grateful he'll be released May 17.
After the announcement of Lopez Rivera's commutation, about 50 people gathered outside the Urban Theater in Chicago's Humboldt Park neighborhood, singing and waving Puerto Rican flags.
Jose Lopez, who is Lopez Rivera's brother, said he was looking forward to sharing some Puerto Rican food with his brother.
"That's something our mother would have wanted," Lopez said.
When asked what he thought his brother might want to do upon his release, Lopez said: "Oscar is a very spiritual person. I'm sure that he's expressed his anxiety to see Puerto Rico, to be in the beaches, to be able to bathe in the sun of Puerto Rico. But also he has one daughter and one granddaughter, which I think are very, very important to him."
Dr. Virginia Boyle, an English teacher at Pedro Albizo Campos High School in Chicago, said she told students to celebrate.
"We were screaming and telling the students, 'Go down the street! It's happening! It's really happening!' " Boyle said.
Lopez Rivera helped found Pedro Albizo Campos High School in 1972, when it was known as La Escuelita Puertorriqueña. Boyle said many of the students at the school recently traveled to Washington D.C. to advocate for his release.
"The students have worked for years to free him," Boyle said.
U.S. Rep. Luis V. Gutierrez, D-Ill., said in a statement that he was "overjoyed and overwhelmed with emotion" at the news of Lopez Rivera's imminent release.
"Oscar is a friend, a mentor, and family to me, and he and his brother José have been friends and mentors for my entire adult life," said Gutierrez, a Puerto Rican born in Chicago. "There were times when hope was hard to find, but my wife Soraida always had faith that this day would come. Now it is clear that Oscar will rejoin his family and be able to walk free among the Puerto Rican people."
WBEZ's Miles Bryan and the Associated Press contributed to this story.