Mr. Edwards at a Washington hearing in 1975. (Associated Press)

Don Edwards, who became dean of the California delegation during 32 years in the House and was one of the chamber’s most steadfast defenders of civil rights and civil liberties, died Oct. 1 at his home in Carmel, Calif. He was 100.

He had complications from strokes, said his daughter-in-law Margaret Edwards.

A wealthy title company executive, former FBI agent and onetime president of the California Young Republicans, Mr. Edwards defied the expectations of an establishmentarian, becoming a liberal crusader, slayer of the House Un-American Activities Committee (HUAC) and advocate for laws to promote the First Amendment and prohibit racial discrimination.

Although he remained on friendly terms with many Republicans, Mr. Edwards said he was persuaded to switch his political affiliation because of HUAC excess in the 1950s and his distaste for the isolationist wing of the GOP. He was elected to the House in 1962 from a newly formed district that included San Jose and a swath of the San Francisco Bay area and set out to focus his legislative efforts on fighting what he considered constitutional abuses.

“When I came here, the 11 states of the Old South practiced apartheid,” he told the Wall Street Journal in 1994. “There was a House Un-American Activities Committee. And the FBI was out of control threatening individual liberties.”

A Navy veteran of World War II, he was one of 16 House members to vote against a 1967 bill to make flag desecration a federal crime. When in 1989 the U.S. Supreme Court ruled to protect flag burning as a form of political protest, Mr. Edwards played a leading and successful role in efforts to prevent a constitutional amendment from overriding the court’s decision.

He told colleagues to “remember that the flag is sturdy, flying proudly through every fierce battle of every war and through times of social upheaval. The Constitution, however, is fragile and can be amended by the votes of legislators caught up in the emotional whirlwinds of the moment.”

Mr. Edwards “was a megaphone for civil rights and civil liberties across the country,” said Larry Gerston, a professor emeritus at San Jose State University. “Coming right off of the McCarthy era . . . he really represented a sharp turn away from a very accusatory period in Congress.”

Mr. Edwards was a mainstay of the Judiciary Committee and participated in the Watergate-era hearings that led to President Richard M. Nixon’s resignation in 1974. Mr. Edwards was among the committee members who voted in favor of all articles of impeachment.

His most prominent committee role was chairman of the subcommittee on civil and constitutional rights — at the time, a power center for initiatives to expand legal protections for minorities and women. Mr. Edwards held the position for more than two decades, until his retirement.

‘Most glorious moment’

By Mr. Edwards’s telling, the “most glorious moment” of his congressional career came during his freshman term with the passage of the benchmark Civil Rights Act of 1964. He strongly backed the Voting Rights Act of 1965 that prohibited discrimination at the polls. Years later, he helped shepherd through Congress extensions of that law.

He also helped push through the Civil Rights Act of 1991, a controversial measure that expanded legal recourse for job discrimination, among other effects, but was criticized by opponents as a racial “quota” bill.

Mr. Edwards also was credited with helping pass the sweeping Americans With Disabilities Act of 1990 and laws guaranteeing fair housing practices.

He reportedly declined higher leadership positions to retain the chairmanship of his subcommittee. He used his perch to monitor the activities of the CIA and his former employer, the FBI.

He turned down a seat on the House Permanent Select Committee on Intelligence, he once told the New York Times, because “I thought I would be trapped by secrecy oaths, and it would interfere with my free speech.”

Republicans complained that Mr. Edwards used his subcommittee to stymie their bills on abortion, school prayer and other causes. The late congressman Henry J. Hyde (R-Ill.) once called Mr. Edwards’s subcommittee “the Bermuda Triangle of proposed constitutional amendments.”

Mr. Edwards was unapologetic. During the Reagan administration, the New York Times reported that he said the Judiciary Committee was “like the little Dutch boy. We’ve got our finger in the dike.’’

Despite his liberalism, he enjoyed the respect of Republican colleagues.

“He is relentlessly liberal, but that’s not a vice,” Hyde told the New York Times upon Mr. Edwards’s retirement. “The battle for the fullest expression of civil liberties is losing a general, not a foot soldier.”

Life in politics

William Donlon Edwards was born Jan. 6, 1915, in San Jose to a family that had achieved success through ownership of a title company.

He received a bachelor of arts degree in 1936 and a bachelor of laws degree in 1938, both from Stanford University. He worked briefly as an FBI agent before joining the Navy and serving in the South Pacific during World War II.

Mr. Edwards formed his own title company after the war and became involved in politics. He was head of the California Young Republicans when Nixon first made a successful run for the Senate in 1950.

Mr. Edwards began moving away from conservatism as HUAC, in his words, “traveled like a carnival through the country” with its investigations into the alleged Communist Party infiltration of Hollywood and the federal workforce.

Having found his political philosophy, Mr. Edwards joined organizations including the United World Federalists, the American Civil Liberties Union and Americans for Democratic Action, of which he served as national president.

In Washington, Mr. Edwards distinguished himself, despite his junior status, as a critic of the Vietnam War and as a leader in the long campaign to eliminate HUAC. In an early roll call on the matter, he joined a tiny minority that voted for its abolition. The clerk was so shocked by the congressman’s bold move, Mr. Edwards recalled, that he was called on to repeat his vote.

The committee, by then renamed the House Committee on Internal Security, died in 1975 with a wily maneuver by Mr. Edwards and Phillip Burton, a fellow California Democrat and chairman of the House Democratic Caucus. They accomplished the feat in basically a procedural move.

“Burton called for a voice vote and pounded the gavel so quickly that few people understood what happened,” political writer John Jacobs recounted in his book, “A Rage for Justice: The Passion and Politics of Phillip Burton.” “Burton and Edwards had just abolished the most infamous and anti-democratic committee of the postwar era.”

His marriages to Nancy Dyer and Clyda Guggenberger ended in divorce. His third wife, Edith Wilkie Edwards, whom he married in 1981, died in 2011.

Survivors include three sons from his first marriage, Leonard P. Edwards and Samuel D. Edwards, both of Los Altos Hills, Calif., and Bruce H. Edwards of Gainesville, Fla., and Milwaukee; a son from his second marriage, Thomas Edwards of Westlake Village, Calif.; and several grandchildren and great-grandchildren. Another son from his second marriage, William Edwards, predeceased him.

After several years in Congress, Mr. Edwards said, he briefly considered stepping down and floated the idea publicly. His announcement did not go unnoticed at the FBI headquarters, then under the direction of J. Edgar Hoover.

For years, the Associated Press wrote, Mr. Edwards kept a framed copy of a document reporting the civil libertarian’s impending departure. Scribbled on the paper was a handwritten comment.

“Good riddance,” read the message, which turned out to be about two decades premature. It was signed with the FBI director’s initial, “H.”