John Doar, Nicholas Katzenbach, Thurgood Marshall

In this Jan. 17, 1966 file photo, Assistant Attorney General John Doar, left, stands with Attorney General Nicholas Katzenbach, center, and Solicitor General Thurgood Marshall as they arrive at the Supreme Court building in Washington to defend the legality of the 1965 Voting Rights Act. Doar, who as a top Justice Department civil rights lawyer in the 1960s fought to protect the rights of black voters and integrate universities in the South, died Tuesday, Nov. 11, 2014 at the age of 92. (AP Photo)

John Doar, who played an integral role in the fight for civil rights as a Department of Justice lawyer, died Nov. 11. He was 92.

The cause of death was congestive heart failure, his son, Burke Doar, told The New York Times.

As an assistant attorney general in charge of the Justice Department’s Civil Rights Division until 1967, Doar was the face of the department in the South, where he helped fight to end segregation and to ensure voting and other rights for Blacks in the region.

The self-described “Lincoln Republican” laid the groundwork for the Civil Rights Act and the Voting Rights Act and aided federal efforts in 1961 to protect the Freedom Riders. Doar escorted James Meredith as the young African-American Air Force veteran integrated the University of Mississippi under the watchful eyes of 500 U.S. marshals in 1962, and also joined civil rights protestors in the Selma to Montgomery march.

In 1967, he led the federal prosecution of 18 people charged in the 1964 killings of civil rights workers Andrew Goodman, Michael Schwerner and James Chaney, who were trying to register Black voters in Mississippi as part of “Freedom Summer.” Doar obtained seven convictions.  The murders were dramatized in the movie “Mississippi Burning.

Attorney General Eric Holder called Doar a “giant” of the Civil Rights Movement, a “personal hero” and one of the greatest leaders of the department.

“He was never far from the front lines of this momentous struggle,” Holder said in a statement. “Brave but unassuming, passionate but unbiased, he repeatedly risked his life to preserve the rule of law and stand up for that which was right.”

Barack Obama, John Doar

In this May 29, 2012 file photo, President Barack Obama awards the Medal of Freedom to John Doar, who handled civil rights cases in the 1960’s, during a ceremony in the East Room of the White House in Washington. Doar, who as a top Justice Department civil rights lawyer in the 1960s fought to protect the rights of black voters and integrate universities in the South, died Tuesday at age 92. (AP Photo/Charles Dharapak, File)

Doar was also involved in the formation of the Lawyers’ Committee for Civil Rights Under Law, which was birthed from President John F. Kennedy’s call in 1963 to marshal the pro bono resources of the private bar to combat racial discrimination. He served as co-chair of the organization from 1971 to 1973.

“During a very tumultuous and highly racialized period of our nation’s history, John Doar took bold and courageous steps to ensure that all Americans were afforded equal opportunities, free of discrimination,” Lawyers’ Committee President and Executive Director Barbara Arnwine said in a statement. “ was instrumental in securing the commitment from law firms around the country to devote significant resources on a pro bono basis on behalf of minority rights. We are tremendously grateful for his leadership and service.”

In 1974, Doar returned from years of private practice to act as chief counsel to the U.S. House of Representatives Judiciary Committee during its investigation of the Watergate scandal. He eventually recommended that President Nixon—whom he said he voted for—should be impeached.

In 2012, President Obama awarded Doar the Presidential Medal of Freedom Award for his lifelong status as a champion of equality and justice for all. On Nov. 11, Obama called Doar “one of the bravest American lawyers of his or any era,” and thanked him for helping to open the door of opportunity to persons of color

“Time and time again, John put his life on the line to make real our country’s promise of equal rights for all,” the president said in his statement. “Without John’s courage and perseverance, Michelle and I might not be where we are today.”