Tom Wicker, one of postwar America's most distinguished journalists, died Friday at his home near Rochester, Vt., of an apparent heart attack. He was 85.

The Hamlet, N.C., native covered the assassination of President John F. Kennedy for The New York Times and became the paper's Washington bureau chief and an iconoclastic political columnist for 25 years.

On Nov. 22, 1963, Wicker, a relatively unknown White House correspondent who had worked at four smaller papers, written several novels under a pen name and, at 37, had established himself as a workhorse of the Times' Washington bureau, was riding in the presidential motorcade as it wound through downtown Dallas, the lone Times reporter on a routine political trip to Texas.

The searing images of that day - the rifleman's shots cracking across Dealey Plaza, the wounded president lurching forward in the open limousine, the blur of speed to Parkland Memorial Hospital and the nation's anguish as the doctors gave way to the priests and a new era - were dictated by Wicker from a phone booth in stark, detailed prose drawn from notes scribbled on a White House itinerary sheet. It filled two front-page columns and the entire second page and vaulted the writer to journalistic prominence overnight.

Nine months later, Wicker, the son of a railroad conductor and UNC Chapel Hill graduate, succeeded the legendary James B. Reston as chief of The Times' 48-member Washington bureau, and two years later he inherited the column of the retiring Arthur Krock, the dean of Washington pundits, who had covered every president since Calvin Coolidge.

In contrast to the conservative pontificating of Krock and the genteel journalism of Reston, Wicker brought a hard-hitting Southern liberal/civil libertarian's perspective to his column, "In the Nation."

Riding waves of change as the effects of the divisive war in Vietnam and America's civil rights struggle swept the country, Wicker applauded President Lyndon B. Johnson and Congress for passage of the Civil Rights Act of 1964 and the Voting Rights Act of 1965, but he took the president to task for deepening American involvement in Southeast Asia.

He denounced President Richard Nixon for covertly bombing Cambodia and in the Watergate scandal accused him of creating the "beginnings of a police state." Nixon put Wicker on his "enemies list" but resigned in disgrace over the Watergate cover-up. Vice President Spiro T. Agnew upbraided Wicker for "irresponsibility and thoughtlessness," but he, too, resigned after pleading guilty to evading taxes on bribes he had taken in office.

The Wicker judgments fell like a hard rain upon all the presidents: Gerald R. Ford, for continuing the war in Vietnam; Jimmy Carter, for "temporizing" in the face of soaring inflation and the Iranian hostage crisis; Ronald Reagan, for dozing through the Iran-Contra scandal; and George H. W. Bush, for letting the Persian Gulf war outweigh educational and health care needs at home.

Wicker's targets also included members of Congress, government secrecy, big business, corrupt labor leaders, racial bigots, prison conditions, television and the news media.

Wicker was a hefty man, 6-feet-2 with a ruddy face, jowls, petulant lips and a lock of unruly hair that dangled on a high forehead. The casual gait, the easygoing manner, the down-home drawl set a tone for audiences but masked a fiery temperament, a ferocious work ethic, a tigerish competitiveness and a stubborn idealism, qualities that made him a perceptive observer of the American scene for more than a half-century.

Thomas Grey Wicker was born on June 18, 1926, in Hamlet. He worked on his high school newspaper and decided to make journalism his career.

After Navy service in World War II, he studied journalism at UNC Chapel Hill, graduating in 1948. Over the next decade, he was an editor and reporter at several newspapers in North Carolina,including The Winston-Salem Journal.