Barney Frank, the brassy, lightning-quick-witted former Massachusetts senator, who for decades was the most prominent gay politician in the country and who was an author of the most significant overhaul of the nation’s financial regulations since the Great Depression, died on May 19 at his home in Ogunquit, Maine. He was 86.

Mr. Frank, a liberal Democrat, represented a diverse suburban Boston district for 32 years, starting in 1981. A Harvard-trained lawyer, Mr. Frank “bristled with intellectual firepower, acidic turns of phrase, and a zest for verbal combat,” The New York Times said.

His most significant legislative achievement was in the realm of financial regulation. The Dodd-Frank Wall Street Reform and Consumer Protection Act, which he sponsored with Senator Christopher Dodd of Connecticut, tightened the rules on the financial industry as part of the government’s response to the housing crisis of 2007 and the global financial meltdown the next year. Signed into law by President Barack Obama in 2010, the measure sought to prevent the nation’s biggest banks from engaging in behavior with risks to consumers.

Mr. Frank’s book, The Hard Path to Unity, completed shortly before he entered hospice care, opined that the political left had sometimes gone too far in pushing divisive causes. “Slow down,” he advised, “and find common ground.” He told interviewers that he was pleased that the book’s message was having some resonance. “Frankly,” he told The Times, “if I weren’t dying, people wouldn’t be paying as much attention.”