Barney Frank, the quick-witted Massachusetts congressman and liberal lion who helped overhaul Wall Street regulations after the 2008 financial crisis and made history as one of the first openly gay members of Congress, died Wednesday, his sister confirmed to NBC Boston.

He was 86. He had entered hospice care at his home in Maine in last month.

“He was, above all else, a wonderful brother. I was lucky to be his sister,” Frank’s sister Doris Breay told NBC Boston.

Frank represented southern Massachusetts in the House for 32 years and established himself as a leading voice in debates over banking, affordable housing and LGBTQ rights. He chaired the Financial Services Committee amid the 2008 meltdown and co-authored the milestone Dodd-Frank Act, a sweeping law that sought to put Wall Street firms under tougher scrutiny.

He blazed a trail for other openly gay American elected officials, and in 2012, he became the first member of Congress to enter into a same-sex marriage, tying the knot with his longtime partner, Jim Ready.

“It was life-changing, lifesaving for me,” Frank told NBC News in a phone interview in last month.

“I think the key to our having made the enormous progress we made in defeating anti-gay prejudice had to do with us all coming out and people discovering the gap between our reality and the way we were painted,” he added.

Rep. Nancy Pelosi, D-Calif., the former House speaker, who served with Frank for more than 25 years, described him as progressive and an idealist in an interview with NBC News last month.

“He has been about idealism and pragmatism to get the job done,” said Pelosi, who was speaker when Frank shepherded Dodd-Frank through Congress. Frank called Pelosi last month to inform her that he was receiving hospice care, she said.

“He was a real mentor to so many of us here,” Pelosi said. “I was with him on [the] Banking [Committee] in the beginning. I learned so much.”

Frank was known for his colorful and sometimes combative persona. He earned a reputation as an eloquent debater, a cutting questioner during hearings and a quotable subject for reporters. In a 2012 interview with The New Republic, for instance, he said President Barack Obama’s effort to “govern in a post-partisan manner” gave him “post-partisan depression.”

Frank did not seek re-election to a 17th term in the House in 2012 and retired from politics the following year.

In a recent interview with Politico, Frank said he was “very proud of Dodd-Frank,” adding: “I think we have been vindicated against our critics from both the left and the right.”

In his final months, he publicly chided his party’s left flank and wrote a book, “The Hard Path to Unity: Why We Must Reform the Left to Rescue Democracy,” set for publication in September.

In an interview with NBC Boston, Frank said he believed the American left was correct on the issue of economic inequality, but he criticized progressives for pushing for sociocultural change “in ways that went beyond what was politically acceptable.”

Barnett Frank was born in Bayonne, New Jersey, on March 31, 1940, and raised in a working-class Jewish household. He showed early academic promise and earned a bachelor’s degree in 1962 from Harvard University, where he stayed for six more years as a government instructor and Ph.D. student.

He left Harvard to take a job as chief of staff to Democratic Boston Mayor Kevin White, serving in the role from 1968 to 1971 during a period of racial tumult in the city. Then came a staff assistant position in the office of Rep. Michael F. Harrington, a Democrat who represented Massachusetts’ 6th Congressional District.

In 1972, Frank entered electoral politics, winning an open seat in the Massachusetts Legislature. He was re-elected three times, earning a J.D. from Harvard Law School while he was serving in the state House, before he climbed the next rung in his political career: a bid for the U.S. House.

In 1980, he was narrowly elected to represent Massachusetts’s 4th Congressional District, winning just under 52% of the vote. The tight margin in his first House race proved to be an anomaly; Frank won his 15 re-election bids handily and became a familiar liberal mainstay in the lower chamber of Congress.

In 1987, during his fourth term in the House, Frank became the first member of Congress to voluntarily come out as gay. (The first was outed during the congressional page scandal four years earlier.) “If you ask the direct question: ‘Are you gay?’ the answer is yes,” Frank told The Boston Globe. “So what?”