NOEL KING, HOST:
Fifty years ago today, an iconic photo of the civil rights movement was snapped on a street in Memphis. But the story behind that inspiring and unforgettable image has many shades of gray. Christopher Blank of WKNO in Memphis has the story.
CHRISTOPHER BLANK, BYLINE: Ernest Withers took more than a million pictures during his lifetime. His daughter, Rosalind, now runs a gallery of his work.
ROSALIND WITHERS: All of these drawers are filled with envelopes of negatives. This is all civil rights.
BLANK: Withers became the de facto photographer of post-World War II African-American life in Memphis, from sporting events to social functions to the civil rights movement. His most famous image now hangs in museums around the world. It shows a wall of men - black sanitation workers - marching for better treatment.
WITHERS: And they are holding that sign that says, I am a man. And when you have to wear a sign that defines who you are, it just shows you how injustice has taken place for you to have to do that.
BLANK: Withers had open access to civil rights leaders, and his pictures helped tell the story of the movement.
WITHERS: He always carried three cameras, and he would chk-chk-chk (ph).
BLANK: One roll of film went to the white press, another to the black press, and the last, he kept. But some of those pictures had an ulterior purpose.
MARC PERRUSQUIA: Ernest provided a lot of information on what they were doing and what their plans were.
BLANK: That's Marc Perrusquia, an investigative reporter and author of the new book "A Spy In Canaan." After Withers' death in 2007, Perrusquia discovered an FBI code name in some government files. Eventually, he learned that Withers had been a paid FBI informant.
PERRUSQUIA: They used Ernest's gravitas as a news photographer. And they would basically tell him, we want you to cover this march under the pretext of a photographer. And they said, we want good identification pictures, face shots.
BLANK: When Martin Luther King Jr. came to Memphis in 1968 to support the sanitation workers' strike, Withers contributed photos and tips to their pool of heavy surveillance. The government was worried that King's next March on Washington, the Poor People's Campaign, could get out of hand.
PERRUSQUIA: The FBI was very much determined to stop him.
BLANK: King was stopped, but by an assassin on April 4, 1968. But the FBI records around him and his associates remained. Some files haunted activists for years. This level of infiltration would later raise questions about Withers' legacy.
EARNESTINE JENKINS: You can't throw it away and not say that it doesn't matter.
BLANK: Dr. Earnestine Jenkins studies civil rights photography at the University of Memphis. She says that many in the movement now feel his double life was a betrayal. Rosalind Withers was as shocked as anyone to learn of her father's past but says his work still tells an essential story.
WITHERS: Our history as African-Americans, it gets lost. And I can truly tell you the era in which my father live has been detailedly (ph) record.
BLANK: Of all the pictures taken by Withers over more than 50 years, a group of striking sanitation workers remains his ultimate image - saturated with hope and despair, a symbol of every struggle where the goal is basic human dignity. For NPR News, I'm Christopher Blank.
(SOUNDBITE OF MAX ROACH AND ABBEY LINCOLN'S "DRIVA MAN") Transcript provided by NPR, Copyright NPR.