Michael Flug, a renowned Chicago library archivist, influenced countless dissertations, articles and books with his knowledge of the Midwest’s biggest trove of materials on African American history.

Though his work often required quiet concentration, he was a friendly gatekeeper and guide, welcoming high school students as warmly as the many researchers who’d visit the Vivian G. Harsh Research Collection of Afro-American History and Literature at the Chicago Public Library system’s Carter G. Woodson Regional Library, 9525 S. Halsted St.

Mr. Flug, a senior archivist who began working at the Woodson library in 1990, died July 11 at his Rogers Park home of a cerebral hemorrhage, his wife Suzanne French said. He was 74.

“The black community is so much better off because of him,” said Julieanna Richardson, founder of HistoryMakers, the biggest collection of African American video oral histories in the United States.

“He was so committed to the perspective that everybody makes history,” said Jacqueline Goldsby, an English and African American studies professor at Yale University.

“Michael is a South Side Institution,” said Davarian L. Baldwin, a history professor at Trinity College in Hartford, Connecticut, and author of “Chicago’s New Negroes: Modernity, the Great Migration, and Black Urban Life.” “I consider him a collaborator.”

“Michael meant so much to so many of us historians of African American history. He helped us with our books, our articles,” said Marcia Walker-McWilliams, who, as a University of Chicago doctoral student, worked with Goldsby and others to help organize research materials at the Woodson library.

Walker-McWilliams remembers him showing her “boxes and boxes, some of them stacked four and five feet deep,” on the Rev. Addie Wyatt, about whom she wrote the 2016 book “Reverend Addie Wyatt: Faith and the Fight for Labor, Gender, and Racial Equality.”

Mr. Flug would slip on cotton archivist’s gloves and quickly locate treasures among the tens of thousands of documents and hundreds of boxes of materials.

Mystery writer Sara Paretsky came to the library to research the New Deal-era Works Progress Administration’s Negro Theatre Project for her novel “Black List.” Paretsky paid homage to Mr. Flug with the character of an able archivist in “Critical Mass” and thanked him in the acknowledgments in her novels. “He really made them deeper, richer books,” she said.

A poem for Michael Flug Award-winning Chicago poet Haki R. Madhubuti, one of the architects of the Black Arts Movement, wrote this tribute to archivist Michael Flug when he retired from the Chicago Public Library’s Carter G. Woodson Regional Library. KEEPING PAPERS ALIVE books altered the culture of his life, a DNA effect that transported him southwest of wherever he was meant to be. yes, books, journals, magazines and newspapers with multiple titles, designations and signatures created in the forms of handwritten prose, typed poetry, undeciphered african languages, scholar’s codes and playwriter’s words, nuances and stage props all spoke to him in rooms never destined to be his, small archival spaces amended before he understood the canons of layered languages rinsed in garlic & hot sauce mixed with black chocolate, negro bottom ideas located on that same southeast corner of southwest chi-town. defending and contemplating memories of woodson, hughes, wright, brooks, colter, perkins and burroughs — all engraved permanently, affectionately among peers and others where readers, scholars and community cluster — encouraged, given pens and bottles of ink. reminding us of earlier writers/poets who craved the feel of black ink to paper creating and exploding ideas, images, themes, characters and then some to make our world advance its logical protocols. you leave prodigious fingerprints.

“He knew every document in that room,” Paretsky said. “He went to different drawers and pulled out the papers of W.E.B. Du Bois’ wife Shirley,” who helped create the 1938 premiere of “Swing Mikado” in Chicago.

“He was excellent at archival management,” said Harsh Collection curator Robert Miller. “He was world-famous.”

“It was as though he held a flashlight into Chicago’s past,” said Don Hayner, a retired Chicago Sun-Times editor-in-chief who said Mr. Flug was generous with help as he worked on his upcoming book “Binga: the Rise and Fall of Chicago’s First Black Banker.”

Though he was white, some people assumed Mr. Flug must be mixed-race, Walker-McWilliams said, “because he knew so much, and he was involved in CORE” — the Congress of Racial Equality — “and the civil rights struggle.”

Mr. Flug was a child of Jewish activist parents in Brooklyn.

“He used to joke he grew up in a family in which he always thought the two-party system was the Communists and Socialists,” his wife said.

French, who was married to Mr. Flug since 1984, said he helped organize civil rights demonstrations in the 1960s in New York and in the South for CORE and was arrested “26 or 27 times” doing so. One of those times was at an anti-segregation protest in Durham, North Carolina, where she said he announced, “I’m happy to be here, brothers and sisters,” and was arrested immediately.

So many were arrested, she said, CORE didn’t have the money to bail them out, and Mr. Flug spent three weeks in jail and was convicted of inciting a riot.

Mr. Flug was a conscientious objector during the Vietnam war, worked as a union organizer in Baltimore and enforced contract compliance for the city of Detroit, going to job sites to ensure there were minority workers, his wife said.

“His whole life has been civil rights of one form or another,” she said.

After his undergraduate studies at Columbia University, he got a master’s degree in archival administration from Wayne State University in Detroit.

In Michigan, he helped organize papers for Raya Dunayevskaya, who had been a secretary to Leon Trotsky, the Russian revolutionary.

For the Harsh Collection, Mr. Flug helped organize papers and photos connected to:

The Abbott-Sengstacke family, founders of the Chicago Defender.

Wally Amos of “Famous Amos” chocolate chip cookie fame.

Historian Timuel Black.

Chester Commodore, the Defender’s editorial cartoonist.

Earl B. Dickerson, who was the lead attorney in the 1940 Hansberry vs. Lee lawsuit challenging housing discrimination. Playwright Lorraine Hansberry used her family’s fight as the basis for “A Raisin in the Sun.”

Capt. Walter Dyett, the band director at DuSable High School whose students included Gene Ammons, Bo Diddley, Nat “King” Cole, Dorothy Donegan, Von Freeman and Dinah Washington.

Marjorie Stewart Joyner, who was national supervisor of the beauty schools founded by Madam C.J. Walker.

Langston Hughes’ “The Big Sea” and Richard Wright’s “Big Boy Leaves Home.”

“Without him, these records would be sitting on a dusty shelf, never being donated at all, because people trusted him,” said Richard Cahan, an author, historian and former Sun-Times picture editor.

In a 2007 interview, Mr. Flug told the Sun-Times: “The collection was built by the community. And that’s what makes it special. This stuff didn’t just magically walk in here. And we didn’t buy it.”

His wife said he liked civil rights anthems like “Ain’t Going to Let Nobody Turn Me Around,” sometimes singing it when he went to pick up the newspaper. He adored his rescue cat Kerry, named for a scenic county in Ireland, one of his favorite places.

“I’d walk in the room, and he’d say, ‘Hello, beautiful,’ and I’d think: ‘How nice.’ He was talking to the cat,” French said, laughing at the memory.

The couple loved traveling, especially to the windswept seaside town of Dunquin, Ireland, a setting for part of the 1970 movie “Ryan’s Daughter.” French said Mr. Flug thought “it’s the most beautiful country, with its own history of struggle.”

She said he also liked going to Michigan, to Sleeping Bear Dunes National Lakeshore and to South Haven, once “one of the few places Jews were allowed to rent cottages in the summer, and a little community up there, Idlewild, where blacks were allowed to rent.”

Of his musical tastes, Walker-McWilliams said, “He was so proud he had seen Tina Turner in concert every decade — the ‘60s, the ‘70s, the ‘80s, the ‘90s.”

In addition to his wife, he is survived by her sons Michael and Kevin French, his brother Jon and two grandchildren. A memorial is planned from 10 a.m. to 2 p.m. Aug. 3 in the lower-level reception hall of the Harold Washington Library Center downtown.