Leonard Weinglass, 77, a lawyer who was called a modern-day Clarence Darrow for defending politically unpopular clients such as the Black Panthers and the Chicago Seven in the 1960s, died March 23 of pancreatic cancer in New York City.

In 1968, Mr. Weinglass was part of the defense team representing the Chicago Seven, a politically radical group accused of various crimes stemming from violence at the Democratic National Convention in Chicago.

“I thought then that Len was the best trial attorney I ever met,” said Tom Hayden, one of the defendants. “We roomed together during the trial, and he taught me to be his sort-of assistant counsel. I think everybody in the courtroom came to realize what an extraordinary lawyer he was.”

Some of the defendants were convicted of crossing state lines with the intent to incite a riot, but an appeals court reversed the convictions. The Justice Department never retried the case.

Later, Mr. Weinglass helped defend Daniel Ellsberg and Anthony Russo, who were charged with leaking the Pentagon Papers in the early 1970s. Criminal charges against the two, who copied and disseminated the classified documents about the U.S. role in the Vietnam War, were eventually dismissed.

Ellsberg said he owed his life to Mr. Weinglass.

“He wasn’t drawn to making money. He was drawn to defending justice,” Ellsberg said. “He felt in many cases he was representing one person standing against the state. He was on the side of the underdog. He was also very shrewd in his judgment of juries.”

Michael Krinsky, a partner at Rabinowitz, Boudin, Standard, Krinsky and Lieberman, where Mr. Weinglass worked, said: “I always considered Lenny the modern-day Clarence Darrow. He was a lawyer who devoted himself to defending people, usually for political reasons. I think one of the reasons he was so effective with juries is they saw his decency and sincerity.”

Leonard Irving Weinglass was born Aug. 27, 1933, in Belleville, N.J. After graduating from George Washington University, he received his law degree from Yale University in 1958.

He served in the Air Force judge advocate’s office from 1959 to 1961, later opened a law office in Newark and soon was representing defendants in civil rights cases.

“It was lonely work, it was dangerous work, but he was making a very vital contribution to the civil rights struggles of the late ’60s,” Krinsky said.

Other high-profile defendants included Angela Davis, a former Black Panther who was acquitted of murder and kidnapping charges in California in 1972.

Another client, Kathy Boudin, was a member of the Weather Underground and was charged with murder during a 1981 robbery of an armored truck in New York.

She was convicted for her role in the holdup and was paroled in 2003.

In the 1970s, Mr. Weinglass unsuccessfully defended members of the radical organization called the Symbionese Liberation Army, which was best known for kidnapping newspaper heiress Patricia Hearst, who later joined forces with her captors and helped them rob a bank in San Francisco.

Mr. Weinglass also worked on the death row appeals of Mumia Abu-Jamal, a former Black Panther convicted in the slaying of a Philadelphia police officer.

In recent years, he took part in the Cuban Five case, in which defendants were accused in Florida of conspiracy to commit espionage for Cuba.

Mr. Weinglass was divorced and had no children.

Survivors include two sisters and a brother.

— Associated Press