Cronkite's longtime chief of staff, Marlene Adler, said Cronkite died at 7:42 p.m. at his Manhattan home surrounded by family. She said the cause of death was cerebral vascular disease.
Cronkite was the face of the "CBS Evening News" from 1962 to 1981, when stories ranged from the assassinations of Kennedy and the Rev. Martin Luther King Jr. to racial and anti-war riots, Watergate and the Iranian hostage crisis.
It was Cronkite who read the bulletins coming from Dallas when Kennedy was shot Nov. 22, 1963, interrupting a live CBS-TV broadcast of the soap opera "As the World Turns."
He died just three days before the 40th anniversary of the moon landing, another earthshaking moment of history linked inexorably with his reporting.
Cronkite was the broadcaster to whom the title "anchorman" was first applied, and he came so identified in that role that eventually his own name became the term for the job in other languages (Swedish anchors are known as Kronkiters; in Holland, they are Cronkiters).
"He was a great broadcaster and a gentleman whose experience, honesty, professionalism and style defined the role of anchor and commentator," CBS Corp. chief executive Leslie Moonves said in a statement.
His 1968 editorial declaring the United States was "mired in stalemate" in Vietnam was seen by some as a turning point in U.S. opinion of the war. He also helped broker the 1977 invitation that took Egyptian President Anwar Sadat to Jerusalem, the breakthrough to Egypt's peace treaty with Israel.
He followed the 1960s space race with open fascination, anchoring marathon broadcasts of major flights from the first suborbital shot to the first moon landing, exclaiming, "Look at those pictures, wow!" as Neil Armstrong stepped on the moon's surface in 1969. In 1998, for CNN, he went back to Cape Canaveral to cover John Glenn's return to space after 36 years.
"He had a passion for human space exploration, an enthusiasm that was contagious, and the trust of his audience. He will be missed," Armstrong said in a statement.
A former wire service reporter and war correspondent, he valued accuracy, objectivity and understated compassion. He expressed liberal views in more recent writings but said he had always aimed to be fair and professional in his judgments on the air.
President Barack Obama called him the "voice of certainty in an uncertain world."
"He invited us to believe in him, and he never let us down. This country has lost an icon and a dear friend, and he will be truly missed," Obama said.
Off camera, Cronkite's stamina and admittedly demanding ways brought him the nickname "Old Ironpants." But to viewers, he was "Uncle Walter," with his jowls and grainy baritone, his warm, direct expression and his trim mustache.
When he summed up the news each evening by stating, "And THAT's the way it is," millions agreed. His reputation survived accusations of bias by Richard Nixon's vice president, Spiro Agnew, and being labeled a "pinko" in the tirades of a fictional icon, Archie Bunker of CBS's "All in the Family."
Two polls pronounced Cronkite the "most trusted man in America": a 1972 "trust index" survey in which he finished No. 1, about 15 points higher than leading politicians, and a 1974 survey in which people chose him as the most trusted television newscaster.
Like fellow Midwesterner Johnny Carson, Cronkite seemed to embody the nation's mainstream. When he broke down as he announced Kennedy's death, removing his glasses and fighting back tears, the times seemed to break down with him.
And when Cronkite took sides, he helped shape the times. After the 1968 Tet offensive, he visited Vietnam and wrote and narrated a "speculative, personal" report advocating negotiations leading to the withdrawal of American troops.
"We have been too often disappointed by the optimism of the American leaders, both in Vietnam and Washington, to have faith any longer in the silver linings they find in the darkest clouds," he said, and concluded, "We are mired in stalemate."
After the broadcast, President Johnson reportedly said, "If I've lost Cronkite, I've lost middle America."
In the fall of 1972, responding to reports in The Washington Post, Cronkite aired a two-part series on Watergate that helped ensure national attention to the then-emerging scandal.
"When the news is bad, Walter hurts," the late CBS president Fred Friendly once said. "When the news embarrasses America, Walter is embarrassed. When the news is humorous, Walter smiles with understanding."
More recently, in a syndicated column, Cronkite defended the liberal record of Democratic presidential candidate John Kerry and criticized the Iraq war and other Bush administration policies.
But when asked by CNN's Larry King if that column was evidence of media bias, Cronkite set forth the distinction between opinion and reporting. "We all have prejudices," he said of his fellow journalists, "but we also understand how to set them aside when we do the job."
Cronkite was the top newsman during the peak era for the networks, when the nightly broadcasts grew to a half-hour and 24-hour cable and the Internet were still well in the future.
As many as 18 million households tuned in to Cronkite's top-rated program each evening. Twice that number watched his final show, on March 6, 1981, compared with fewer than 10 million in 2005 for the departure of Dan Rather, Cronkite's successor.
"Walter loved reporting and delivering the news, and he was superb at both," Rather said. "He deserves recognition and remembrance, too, for the way he solidly backed his correspondents and producers, defending them vigorously in coverage of difficult stories such as the Vietnam War and the Watergate crimes."
After he retired, he hosted or narrated specials on public and cable TV, and issued his columns and the best-selling "Walter Cronkite: A Reporter's Life."
For 24 years he served as on-site host for New Year's Day telecasts by the Vienna Philharmonic, ending that cherished tradition only in 2009.
Cronkite joined CBS in 1950, after a decade with United Press, during which he covered World War II and the Nuremberg trials, and a brief stint with a regional radio group.
At CBS he found a respected radio-news organization dipping its toe into TV, and it put him in front of the camera. He was named anchor for CBS's coverage of the 1952 political conventions, the first year the presidential nominations got wide TV coverage.
On April 16, 1962, he replaced Douglas Edwards as anchor of the network's "Evening News."
"I never asked them why," Cronkite recalled in a 2006 TV portrait. "I was so pleased to get the job, I didn't want to endanger it by suggesting that I didn't know why I had it."
Cronkite won numerous Emmys and other awards for excellence in news coverage. In 1978, he and the evening news were the first anchorman and daily broadcast ever given a DuPont award.
His salary reportedly reaching seven figures, he was both anchorman and star — interviewed by Playboy, ham enough to appear as himself on an episode of "The Mary Tyler Moore Show." But Cronkite repeatedly condemned television practices that put entertainment values ahead of news judgment.
"Broadcast journalism is never going to substitute for print," he said. "We cannot cover in depth in a half hour many of the stories required to get a good understanding of the world."
Walter Leland Cronkite Jr. was born Nov. 4, 1916, in St. Joseph, Missouri, the son and grandson of dentists. The family moved to Houston when he was 10.
Cronkite quit high-school for a full-time job with the Houston Press. After a brief stint at KCMO in Kansas City, Missouri, he joined United Press in 1937. Dispatched to London early in World War II, Cronkite covered the battle of the North Atlantic, flew on a bombing mission over Germany and glided into Holland with the 101st Airborne Division. He was a chief correspondent at the postwar Nuremberg trials and spent his final two years with the news service managing its Moscow bureau.
Cronkite returned to the United States in 1948 and covered Washington for a group of Midwest radio stations. He then accepted Edward R. Murrow's invitation to join CBS in 1950.
In 1940, Cronkite married Mary Elizabeth "Betsy" Maxwell, whom he had met when they both worked at KCMO. They had three children, Nancy, Mary Kathleen and Walter Leland III. Betsy Cronkite died in 2005.
Morley Safer, a longtime "60 Minutes" correspondent, said: "The trust that viewers placed in him was based on the recognition of his fairness, honesty and strict objectivity ... and of course his long experience as a shoe-leather reporter covering everything from local politics to World War II and its aftermath in the Soviet Union."
"He was a giant of journalism and privately one of the funniest, happiest men I've ever known," Safer said.