Martin R. Stolar, a prominent civil rights lawyer who in the early 1970s defended war resisters and inmates who rebelled at Attica prison, as well as initiating a landmark case restraining the New York Police Department from spying on left-wing activists, died on July 1 in Manhattan. He was 81.

His wife, Elsie Chandler, said he died in a hospital after suffering heart failure while awaiting surgery for a broken hip.

Mr. Stolar was one of a generation of idealistic lawyers who, inspired by the civil rights and anti-Vietnam War movements, forsook lucrative careers to lend their expertise to social justice causes.

“He had a practice that not only defended needy people, it propelled social movements,” said Franklin Siegel, a Distinguished Lecturer at the City University of New York School of Law, who knew Mr. Stolar for nearly six decades.

The righteous fervor of others in the so-called movement dimmed over the years, but Mr. Stolar’s did not. If anything, it got more feisty.

Weeks before his death, he was on an organizing call about defending Columbia University students who had been arrested for protesting the Gaza war. He was also offering advice on defending climate protesters arrested after targeting Wall Street banks for financing fossil fuel projects.