Moore died Thursday of natural causes at a nursing home in Palm Beach Gardens, Fla., said his daughter Michelle Moore Peel.
From 1958 to 1965, he trained his lens on the unfolding drama of civil rights as a news photographer for the Montgomery (Ala.) Advertiser and Life magazine.
His shockingly graphic images -- of police dogs attacking protesters or marchers being assaulted by powerful water hoses -- helped propel what had been a regional dispute onto the national stage.
As his photographs created national outrage, they quickened the passage of the Civil Rights Act of 1964, according to John Kaplan, a University of Florida journalism professor who wrote his master's thesis on Moore.
"He had the courage to stand up in the face of danger and let Americans know what was really happening, through his work," Kaplan told The Times. "That is why he is an unsung hero."
As Moore followed the struggle, he was known for his fearlessness and uncanny knack for capturing the most distressing images possible.
"To people who were really bigoted, I was the worst enemy, a Southern boy working for Life," Moore told USA Today in 1991.
"I knew the South. . . . I also knew how to talk back to racists."
The son of a Baptist minister, Moore was drawn to photographing the Rev. Martin Luther King Jr., then a Baptist clergyman in Montgomery. After witnessing King's charisma firsthand in 1958, Moore sought to cover him whenever possible.
"I knew that this was a man who was going to make a difference," Moore said of King in the 2005 documentary “Charles Moore: I Fight With My Camera.” Moore had yet to realize that his pictures would also make a difference.
A photograph he took in 1958 of King being manhandled during a police booking ran in Life and became "one of the most significant photographs of the civil rights movement," Kaplan wrote in his thesis.
Through the magazine, Moore's work gained a huge national audience. Life had him cover the rioting over the enrollment of James Meredith as the first black student at the University of Mississippi in 1962 and later published his photos of Ku Klux Klan gatherings.
His photographs in Life "electrified and horrified the country," CBS News reported in 1991.
Moore's most influential pictures were taken over five days in 1963 during the campaign to desegregate Birmingham, Ala., Kaplan said. One famous photo -- Moore crawled across pavement, positioning himself between protesters and firemen to get the shot -- showed three students being thrust against a building by high-pressure water from a fire hose.
Covering civil rights "was difficult, exhausting and oftentimes very dangerous," Moore said in the documentary. "Plus troubling and emotional . . . because I'm a Southerner too."
By 1965, he had grown weary of the violence and booked a round-the-world airplane ticket. He came home eight months later.
Charles Lee Moore was born March 9, 1931, in the Alabama farming town of Hackleburg and grew up in nearby Tuscumbia.
As a teenager, he took up boxing and owned his first camera, a Brownie.
After a stint as a Marine Corps photographer, he studied fashion photography at Brooks Institute of Photography in Santa Barbara.
Returning to Alabama in 1957, he briefly worked in a portrait studio before joining the Montgomery Advertiser newspaper staff.
He moved to New York in 1962 to pursue a freelance career but the Black Star photo agency, which still represents him, gave him a stipend and persuaded him to continue covering civil rights. Moore went on to photograph political unrest in Haiti and Venezuela and document the Vietnam War.
In later years, he took travel photographs, corporate portraits and the occasional hard-news photograph. He also amassed about 100 magazine covers.
His work was gathered in two books, "Powerful Days: The Civil Rights Photography of Charles Moore" (1991) and "The Mother Lode," a 1983 pictorial guide to the California gold rush country he came to know as a longtime resident of Columbia, Calif.
Moore, who was divorced, also had lived in Massachusetts and North Carolina. He moved to Florida last year to be near family.
The genteel Moore could seem embarrassed by the attention he received for his most famous body of work.
"I know the importance isn't me, but the photographs," he told the Birmingham News in 2002.
"It's proof that the world learned a lot from them. Honestly, if those pictures made my native South, which I love, a better place . . . then I am darn proud of that."
In addition to his daughter Michelle of West Palm Beach, Fla., Moore is survived by three other children, Michael Moore and April Marshall of Dothan, Ala., and Gary Moore of Lewisville, Texas; his brother, Jim, of Conway, Mass.; seven grandchildren; and three great-grandchildren.